UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM N-Q QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY Investment Company Act file number 811-06540 Name of Fund: BlackRock MuniYield Insured Fund, Inc. Fund Address: P.O. Box 9011 Princeton, NJ 08543-9011 Name and address of agent for service: Robert C. Doll, Jr., Chief Executive Officer (principal executive officer), BlackRock MuniYield Insured Fund, Inc., 800 Scudders Mill Road, Plainsboro, NJ, 08536. Mailing address: P.O. Box 9011, Princeton, NJ, 08543-9011 Registrant's telephone number, including area code: (800) 882-0052 Date of fiscal year end: 10/31/2007 Date of reporting period: 05/01/2007 - 07/31/2007 Item 1 - Schedule of Investments BlackRock MuniYield Insured Fund, Inc. Schedule of Investments as of July 31, 2007 (Unaudited) (in Thousands) Face State Amount Municipal Bonds Value ----------------------------------------------------------------------------------------------------------------------------------- Alaska - 0.4% $ 3,695 Alaska Energy Authority, Power Revenue Refunding Bonds (Bradley Lake), Fourth Series, 6% due 7/01/2018 (g) $ 4,220 ----------------------------------------------------------------------------------------------------------------------------------- Arizona - 2.2% 21,355 Downtown Phoenix Hotel Corporation, Arizona, Revenue Bonds, Senior Series A, 5% due 7/01/2036 (c) 22,050 ----------------------------------------------------------------------------------------------------------------------------------- California - 33.5% 10,000 Alameda Corridor Transportation Authority, California, Capital Appreciation Revenue Refunding Bonds, Subordinate Lien, Series A, 5.40% due 10/01/2024 (a)(q) 8,240 5,000 Antioch, California, Public Finance Authority, Lease Revenue Refunding Bonds (Municipal Facilities Project), Series A, 5.50% due 1/01/2032 (b) 5,221 8,200 California HFA, Home Mortgage Revenue Bonds, VRDN, Series F, 3.66% due 2/01/2033 (a)(h) 8,200 10,000 California Infrastructure and Economic Development Bank, Bay Area Toll Bridges Revenue Bonds, First Lien, Series A, 5% due 7/01/2025 (c)(i) 10,894 10,945 California State, GO, 5.50% due 4/01/2014 (b)(f) 12,018 640 California State, GO, 5.50% due 4/01/2030 (b) 696 17,400 California State, GO, Refunding, 5% due 6/01/2037 17,861 5,500 California State Public Works Board, Lease Revenue Bonds (Department of Corrections), Series C, 5.25% due 6/01/2028 5,722 3,755 California State Public Works Board, Lease Revenue Bonds (Department of General Services), Series D, 5.25% due 6/01/2028 3,906 5,250 California State Public Works Board, Lease Revenue Bonds (Department of Mental Health - Coalinga State Hospital), Series A, 5.125% due 6/01/2029 5,410 16,850 California State Public Works Board, Lease Revenue Bonds (Office of Emergency Services), Series A, 5% due 3/01/2032 (c) 17,444 12,000 California State, Various Purpose, GO, 5.25% due 11/01/2029 12,578 25,000 California State, Various Purpose, GO, Refunding, 5% due 6/01/2034 (d) 25,766 7,740 California Statewide Communities Development Authority, Health Facility Revenue Bonds (Memorial Health Services), Series A, 6% due 10/01/2023 8,323 4,205 California Statewide Communities Development Authority, Water Revenue Bonds (Pooled Financing Program), Series C, 5.25% due 10/01/2034 (g) 4,394 5,800 Fairfield-Suisun, California, Unified School District, GO (Election of 2002), 5.50% due 8/01/2028 (b) 6,257 1,000 Long Beach, California, Harbor Revenue Refunding Bonds, AMT, Series B, 5.20% due 5/15/2027 (b) 1,037 16,000 Los Angeles, California, Department of Water and Power, Waterworks Revenue Bonds, Sub-Series A-2, 5% due 7/01/2044 (a) 16,566 10,000 Los Angeles, California, Municipal Improvement Corporation, Lease Revenue Bonds, Series B1, 4.75% due 8/01/2032 (c) 9,919 15,000 Los Angeles, California, Municipal Improvement Corporation, Lease Revenue Bonds, Series B1, 4.75% due 8/01/2037 (c) 14,787 Portfolio Abbreviations To simplify the listings of BlackRock MuniYield Insured Fund, Inc.'s portfolio holdings in the Schedule of Investments, we have abbreviated the names of many of the securities according to the list below. AMT Alternative Minimum Tax (subject to) COP Certificates of Participation EDA Economic Development Authority GO General Obligation Bonds HDA Housing Development Authority HFA Housing Finance Agency IDA Industrial Development Authority IDR Industrial Development Revenue Bonds S/F Single-Family VRDN Variable Rate Demand Notes BlackRock MuniYield Insured Fund, Inc. Schedule of Investments as of July 31, 2007 (Unaudited) (in Thousands) Face State Amount Municipal Bonds Value ----------------------------------------------------------------------------------------------------------------------------------- $ 12,775 Los Angeles, California, Water and Power Revenue Bonds (Power System), Series B, 5% due 7/01/2035 (g) $13,165 35,200 Los Angeles, California, Water and Power Revenue Bonds (Power System), Sub-Series A-1, 5% due 7/01/2035 (g) 36,502 7,500 Modesto, California, Irrigation District, COP, Refunding and Capital Improvements, Series A, 5% due 10/01/2036 (a) 7,750 10,365 Pasadena, California, Area Community College District, GO (Election of 2002), Series B, 5% due 8/01/2031 (a) 10,807 145 Port of Oakland, California, Revenue Bonds, AMT, Series K, 5.75% due 11/01/2021 (c) 151 6,615 Poway, California, Unified School District, Public Financing Authority, Special Tax Revenue Bonds, 4.50% due 9/15/2037 (a) 6,331 6,930 Riverside, California, Community College District, GO (Election of 2004), Series C, 5% due 8/01/2032 (b) 7,249 10,000 Riverside County, California, Public Financing Authority, Tax Allocation Revenue Bonds (Redevelopment Projects), 5% due 10/01/2035 (e) 10,247 4,000 San Francisco, California, Bay Area Rapid Transit District, GO (Election of 2004), Series B, 5% due 8/01/2035 4,179 10,000 San Francisco, California, Bay Area Rapid Transit District, Sales Tax Revenue Bonds, 5% due 7/01/2036 (g) 10,324 8,170 San Francisco, California, Community College District, GO (Election of 2001), Series C, 5% due 6/15/2029 (g) 8,526 3,250 San Mateo, California, Union High School District, COP (Phase One Projects), Series B, 4.76% due 12/15/2043 (a)(q) 1,802 8,310 Stockton, California, Public Financing Authority, Lease Revenue Bonds (Parking & Capital Projects), 5.25% due 9/01/2034 (c) 8,696 12,000 West Valley Mission Community College District, California, GO (Election of 2004), Series A, 5% due 8/01/2030 (g) 12,521 ----------------------------------------------------------------------------------------------------------------------------------- Colorado - 2.3% 15,000 Aurora, Colorado, Water Improvement Revenue Bonds, First Lien, Series A, 5% due 8/01/2039 (a) 15,623 8,000 Colorado HFA, S/F Mortgage Revenue Refunding Bonds, AMT, Series A-3, Class III, 4.80% due 11/01/2037 (b) 7,660 ----------------------------------------------------------------------------------------------------------------------------------- District of Columbia - 2.6% 25,000 District of Columbia, Ballpark Revenue Bonds, Series B-1, 5% due 2/01/2031 (c) 25,893 ----------------------------------------------------------------------------------------------------------------------------------- Florida - 2.7% 1,000 Miami-Dade County, Florida, Aviation Revenue Refunding Bonds (Miami International Airport), AMT, 5.375% due 10/01/2027 (c) 1,038 25,000 Miami-Dade County, Florida, Aviation Revenue Refunding Bonds (Miami International Airport), AMT, Series A, 5% due 10/01/2039 (b) 25,367 ----------------------------------------------------------------------------------------------------------------------------------- Georgia - 2.0% 12,500 Atlanta, Georgia, Airport General Revenue Refunding Bonds, Series B, 5.25% due 1/01/2033 (g) 13,135 6,250 Fulton County, Georgia, Development Authority Revenue Bonds (Georgia Tech North Avenue Apartments Project), Series A, 5% due 6/01/2032 (e) 6,491 ----------------------------------------------------------------------------------------------------------------------------------- Hawaii - 0.5% 2,000 Hawaii State, GO, Series CX, 5.50% due 2/01/2021 (g) 2,118 3,000 Hawaii State Harbor System Revenue Bonds, AMT, Series A, 5% due 1/01/2031 (g) 3,051 ----------------------------------------------------------------------------------------------------------------------------------- Idaho - 0.8% 4,790 Idaho Housing and Financing Association, S/F Mortgage Revenue Bonds, AMT, Series F-1, Class I, 5.20% due 1/01/2039 4,822 3,555 Idaho Housing and Financing Association, S/F Mortgage Revenue Bonds, AMT, Series G-1, Class III, 5.125% due 1/01/2029 3,567 ----------------------------------------------------------------------------------------------------------------------------------- Illinois - 5.9% 15,400 Chicago, Illinois, GO, Series C, 5% due 1/01/2035 (b) 15,799 1,500 Chicago, Illinois, O'Hare International Airport, Revenue Refunding Bonds, Third Lien, AMT, Series C-2, 5.25% due 1/01/2034 (e) 1,549 22,745 Illinois State Finance Authority Revenue Bonds (Palos Community Hospital), Series A, 5% due 5/15/2035 (e) 23,436 5,000 Illinois State, GO, 5% due 4/01/2028 (a) 5,180 4,820 McLean and Woodford Counties, Illinois, Community Unit School District Number 005, GO, Refunding, 6.375% due 12/01/2011 (f)(g) 5,299 BlackRock MuniYield Insured Fund, Inc. Schedule of Investments as of July 31, 2007 (Unaudited) (in Thousands) Face State Amount Municipal Bonds Value ----------------------------------------------------------------------------------------------------------------------------------- $ 1,215 McLean and Woodford Counties, Illinois, Community Unit School District Number 005, GO, Refunding, 6.375% due 12/01/2016 (g) $ 1,333 4,800 Metropolitan Pier and Exposition Authority, Illinois, Dedicated State Tax Revenue Refunding Bonds (McCormick Place Expansion Project), Series B, 5.75% due 6/15/2023 (b) 5,175 1,000 Regional Transportation Authority, Illinois, Revenue Bonds, Series C, 7.75% due 6/01/2020 (c) 1,290 ----------------------------------------------------------------------------------------------------------------------------------- Indiana - 3.2% 2,250 Indiana Health Facilities Financing Authority, Hospital Revenue Bonds (Deaconess Hospital Obligated Group), Series A, 5.375% due 3/01/2034 (a) 2,372 19,000 Indiana Transportation Finance Authority, Highway Revenue Bonds, Series A, 5.25% due 6/01/2014 (c)(f) 20,525 2,000 Indianapolis, Indiana, Local Public Improvement Bond Bank, Revenue Refunding Bonds (Indianapolis Airport Authority Project), AMT, Series B, 5.25% due 1/01/2028 (b) 2,088 6,525 Indianapolis, Indiana, Local Public Improvement Bond Bank, Revenue Refunding Bonds (Indianapolis Airport Authority Project), AMT, Series B, 5.25% due 1/01/2030 (b) 6,799 ----------------------------------------------------------------------------------------------------------------------------------- Kentucky - 2.3% 7,000 Kentucky Housing Corporation, Housing Revenue Bonds, AMT, Series C, 4.80% due 7/01/2037 6,694 15,000 Louisville and Jefferson Counties, Kentucky, Metropolitan Sewer District, Sewer and Drain System Revenue Bonds, Series A, 5.25% due 5/15/2037 (c) 16,025 ----------------------------------------------------------------------------------------------------------------------------------- Louisiana - 2.4% 3,750 Louisiana Local Government Environmental Facilities and Community Development Authority, Revenue Bonds (Capital Projects and Equipment Acquisition), Series A, 6.30% due 7/01/2030 (a) 4,372 6,615 Louisiana Public Facilities Authority, Hospital Revenue Bonds (Franciscan Missionaries of Our Lady Health System, Inc.), Series A, 5.25% due 8/15/2036 6,701 4,270 Louisiana Public Facilities Authority Revenue Bonds (Nineteenth Judicial District Court Building Project), 5.50% due 6/01/2041 (c) 4,617 4,500 Louisiana State, Gas and Fuels Tax Revenue Bonds, Series A, 5% due 5/01/2025 (e) 4,674 3,545 New Orleans, Louisiana, GO (Public Improvements), 5% due 10/01/2033 (b) 3,630 ----------------------------------------------------------------------------------------------------------------------------------- Massachusetts - 10.3% 2,500 Massachusetts State, HFA, Housing Development Revenue Refunding Bonds, Series B, 5.40% due 12/01/2028 (b) 2,551 12,365 Massachusetts State, HFA, Rental Housing Mortgage Revenue Bonds, AMT, Series A, 5.15% due 7/01/2026 (g) 12,572 10,000 Massachusetts State Health and Educational Facilities Authority, Revenue Refunding Bonds (Berklee College of Music), Series A, 5% due 10/01/2037 10,207 7,550 Massachusetts State Port Authority Revenue Bonds, Series A, 5% due 7/01/2033 (b) 7,772 19,755 Massachusetts State Port Authority, Special Facilities Revenue Refunding Bonds (BOSFUEL Project), AMT, 5% due 7/01/2038 (c) 20,016 16,060 Massachusetts State School Building Authority, Dedicated Sales Tax Revenue Bonds, Series A, 4.50% due 8/15/2035 (a) 15,562 22,000 Massachusetts State School Building Authority, Dedicated Sales Tax Revenue Bonds, Series A, 5% due 8/15/2037 (a) 22,935 10,000 Massachusetts State Special Obligation Dedicated Tax Revenue Bonds, 5.75% due 1/01/2014 (c)(f) 11,017 ----------------------------------------------------------------------------------------------------------------------------------- Michigan - 3.5% 4,325 Michigan Higher Education Student Loan Authority, Student Loan Revenue Bonds, AMT, Series XVII-Q, 5% due 3/01/2031 (a) 4,388 10,000 Michigan State, HDA, Rental Housing Revenue Bonds, AMT, Series B, 4.95% due 4/01/2044 (g) 9,639 20,000 Wayne County, Michigan, Airport Authority Revenue Bonds (Detroit Metropolitan Wayne County Airport), AMT, 5% due 12/01/2029 (b) 20,408 ----------------------------------------------------------------------------------------------------------------------------------- BlackRock MuniYield Insured Fund, Inc. Schedule of Investments as of July 31, 2007 (Unaudited) (in Thousands) Face State Amount Municipal Bonds Value ----------------------------------------------------------------------------------------------------------------------------------- Missouri - 0.5% $ 130 Missouri State Housing Development Commission, S/F Mortgage Revenue Bonds (Homeownership Loan Program), AMT, Series C-1, 7.15% due 3/01/2032 (k) $ 138 5,000 Missouri State Housing Development Commission, S/F Mortgage Revenue Refunding Bonds (Homeownership Loan Program), AMT, Series D-1, 5% due 9/01/2037 (k)(l) 4,938 ----------------------------------------------------------------------------------------------------------------------------------- Nebraska - 1.6% 15,435 Nebraska Public Power District Revenue Bonds, Series A, 5% due 1/01/2035 (a) 15,878 ----------------------------------------------------------------------------------------------------------------------------------- Nevada - 3.3% 25,000 Clark County, Nevada, Airport System Subordinate Lien Revenue Bonds, Series A-2, 5% due 7/01/2030 (c) 25,705 6,000 Henderson, Nevada, Health Care Facilities Revenue Bonds (Catholic Healthcare West), Series A, 5.625% due 7/01/2024 6,306 1,165 Reno, Nevada, Capital Improvement Revenue Bonds, 5.50% due 6/01/2019 (c) 1,235 ----------------------------------------------------------------------------------------------------------------------------------- New Hampshire - 0.7% 6,685 New Hampshire State, HFA, S/F Mortgage Revenue Refunding Bonds, AMT, Series A, 4.85% due 1/01/2038 6,436 ----------------------------------------------------------------------------------------------------------------------------------- New Jersey - 4.8% 16,000 Garden State Preservation Trust of New Jersey, Open Space and Farmland Preservation Revenue Bonds, Series A, 5.75% due 11/01/2028 (g) 18,912 3,060 New Jersey EDA, Cigarette Tax Revenue Bonds, 5.75% due 6/15/2029 3,258 2,610 New Jersey EDA, Cigarette Tax Revenue Bonds, 5.50% due 6/15/2031 2,729 14,135 New Jersey EDA, Cigarette Tax Revenue Bonds, 5.75% due 6/15/2034 14,983 20,000 New Jersey State Transportation Trust Fund Authority, Transportation System Revenue Bonds, Series C, 4.96% due 12/15/2035 (a)(p) 5,178 2,880 Newark, New Jersey, Housing Authority, Port Authority-Port Newark Marine Terminal Additional Rent-Backed Revenue Bonds (City of Newark Redevelopment Projects), 5.50% due 1/01/2014 (b)(f) 3,139 ----------------------------------------------------------------------------------------------------------------------------------- New Mexico - 0.7% 1,605 New Mexico Educational Assistance Foundation, Student Loan Revenue Refunding Bonds (Student Loan Program), AMT, First Sub-Series A-2, 6.65% due 11/01/2025 1,633 410 New Mexico Mortgage Finance Authority, S/F Mortgage Revenue Bonds, AMT, Series C-2, 6.95% due 9/01/2031 (k) 420 5,000 New Mexico Mortgage Finance Authority, S/F Mortgage Revenue Bonds, AMT, Series C-2, 5% due 7/01/2038 (k)(l) 4,930 ----------------------------------------------------------------------------------------------------------------------------------- New York - 13.7% 29,750 Hudson Yards Infrastructure Corporation, New York, Revenue Bonds, Series A, 4.50% due 2/15/2047 (b) 28,301 10,250 Long Island Power Authority, New York, Electric System Revenue Bonds, Series A, 5.10% due 9/01/2029 10,623 5,335 Metropolitan Transportation Authority, New York, Commuter Facilities Revenue Refunding Bonds, Series B, 5.125% due 7/01/2024 (a)(i) 5,447 30,000 New York City, New York, City Municipal Water Finance Authority, Water and Sewer System, Revenue Refunding Bonds, Series B, 5% due 6/15/2036 (g) 30,988 1,880 New York City, New York, GO, Series B, 5.875% due 8/01/2016 (b) 2,004 10,000 New York City, New York, GO, Series J, 5.25% due 5/15/2024 10,566 1,000 New York City, New York, GO, Series J, 5.25% due 5/15/2025 1,056 20,000 New York City, New York, GO, Series M, 5% due 4/01/2030 (n) 20,720 6,000 New York City, New York, GO, Sub-Series C-1, 5.25% due 8/15/2026 6,343 19,500 Port Authority of New York and New Jersey, Consolidated Revenue Bonds, AMT, 137th Series, 5.125% due 7/15/2030 (g) 20,199 ----------------------------------------------------------------------------------------------------------------------------------- North Carolina - 0.5% 5,000 Charlotte, North Carolina, Airport Revenue Refunding Bonds, VRDN, AMT, Series A, 3.68% due 7/01/2017 (b)(h) 5,000 ----------------------------------------------------------------------------------------------------------------------------------- BlackRock MuniYield Insured Fund, Inc. Schedule of Investments as of July 31, 2007 (Unaudited) (in Thousands) Face State Amount Municipal Bonds Value ----------------------------------------------------------------------------------------------------------------------------------- Oregon - 2.2% $ 10,000 Clackamas County, Oregon, School District Number 12, GO (North Clackamas), Series A, 4.50% due 6/15/2030 (g) $ 9,804 12,380 Clackamas County, Oregon, School District Number 12, GO (North Clackamas), Series A, 4.50% due 6/15/2032 (g) 12,072 ----------------------------------------------------------------------------------------------------------------------------------- South Carolina - 6.6% 5,000 Berkeley County, South Carolina, School District, Installment Lease Revenue Bonds (Securing Assets for Education Project), 5.125% due 12/01/2030 5,178 3,895 Charleston Educational Excellence Financing Corporation, South Carolina, Revenue Bonds (Charleston County School District), 5.25% due 12/01/2028 (n) 4,118 3,465 Charleston Educational Excellence Financing Corporation, South Carolina, Revenue Bonds (Charleston County School District), 5.25% due 12/01/2029 (n) 3,659 1,160 Charleston Educational Excellence Financing Corporation, South Carolina, Revenue Bonds (Charleston County School District), 5.25% due 12/01/2030 (n) 1,224 3,775 Kershaw County, South Carolina, Public Schools Foundation, Installment Power Revenue Refunding Bonds, 5% due 12/01/2030 (d) 3,891 3,690 Kershaw County, South Carolina, Public Schools Foundation, Installment Power Revenue Refunding Bonds, 5% due 12/01/2031 (d) 3,801 10,000 Lexington County, South Carolina, Health Services District Inc., Hospital Revenue Refunding Bonds, 5% due 11/01/2032 9,928 930 South Carolina Housing Finance and Development Authority, Mortgage Revenue Refunding Bonds, AMT, Series A-2, 6.35% due 7/01/2019 (g) 958 6,500 South Carolina State Public Service Authority, Revenue Refunding Bonds, Series A, 5% due 1/01/2037 (a) 6,747 7,200 South Carolina State Public Service Authority, Revenue Refunding Bonds, Series A, 5% due 1/01/2042 (a) 7,423 18,030 South Carolina Transportation Infrastructure Bank Revenue Bonds, Series A, 5% due 10/01/2029 (a) 18,583 ----------------------------------------------------------------------------------------------------------------------------------- Tennessee - 0.9% 1,795 Tennessee HDA, Revenue Bonds (Homeownership Program), AMT, Series 2C, 6.05% due 7/01/2012 1,837 2,250 Tennessee HDA, Revenue Bonds (Homeownership Program), AMT, Series 2C, 6.15% due 7/01/2014 2,288 3,050 Tennessee HDA, Revenue Refunding Bonds (Homeownership Program), AMT, Series A, 5.25% due 7/01/2022 (g) 3,096 2,160 Tennessee HDA, Revenue Refunding Bonds (Homeownership Program), AMT, Series A, 5.35% due 1/01/2026 (g) 2,191 ----------------------------------------------------------------------------------------------------------------------------------- Texas - 12.7% 1,880 Bexar, Texas, Metropolitan Water District, Waterworks System Revenue Refunding Bonds, 6.35% due 5/01/2025 (b) 1,884 1,000 Dallas-Fort Worth, Texas, International Airport, Joint Revenue Bonds, AMT, Series A, 5% due 11/01/2035 (g) 1,002 1,665 Harris County-Houston Sports Authority, Texas, Revenue Refunding Bonds, Senior Lien, Series G, 5.75% due 11/15/2019 (b) 1,768 3,500 Harris County-Houston Sports Authority, Texas, Revenue Refunding Bonds, Senior Lien, Series G, 5.75% due 11/15/2020 (b) 3,716 10,000 Harris County-Houston Sports Authority, Texas, Revenue Refunding Bonds, Senior Lien, Series G, 5.25% due 11/15/2030 (b) 10,396 10,695 Houston, Texas, Combined Utility System, First Lien Revenue Refunding Bonds, Series A, 5% due 11/15/2036 (g) 11,077 12,865 North Texas Health Facilities Development Corporation, Hospital Revenue Refunding Bonds (United Regional Health Care System), 5% due 9/01/2032 (g) 13,245 15,000 North Texas Municipal Water District, Texas, Water System Revenue Bonds, 5% due 9/01/2031 (b) 15,565 5,890 North Texas Thruway Authority, Dallas North Thruway System Revenue Bonds, Series A, 5% due 1/01/2035 (g) 6,055 5,400 Panhandle-Plains Higher Education Authority Inc., Texas, Student Loan Revenue Bonds, VRDN, AMT, Series A, 3.68% due 6/01/2023 (b)(h) 5,400 BlackRock MuniYield Insured Fund, Inc. Schedule of Investments as of July 31, 2007 (Unaudited) (in Thousands) Face State Amount Municipal Bonds Value ----------------------------------------------------------------------------------------------------------------------------------- $ 15,000 SA Energy Acquisition Public Facilities Corporation, Texas, Gas Supply Revenue Bonds, 5.50% due 8/01/2027 $ 16,040 4,825 Texas State Department of Housing and Community Affairs, S/F Mortgage Revenue Bonds, AMT, Series A, 5.45% due 9/01/2023 (b)(k) 4,918 10,000 Texas State Turnpike Authority, Central Texas Turnpike System Revenue Bonds, First Tier, Series A, 5.50% due 8/15/2039 (a) 10,580 24,500 Waco, Texas, Health Facilities Development Corporation, Mortgage Revenue Bonds (Hillcrest Health System Projects), Series A, 5% due 8/01/2031 (b)(r) 25,216 ----------------------------------------------------------------------------------------------------------------------------------- Vermont - 0.1% 515 Vermont HFA, S/F Housing Revenue Bonds, AMT, Series 12B, 6.30% due 11/01/2019 (g) 520 ----------------------------------------------------------------------------------------------------------------------------------- Virginia - 1.1% 3,250 Fairfax County, Virginia, EDA, Residential Care Facilities, Mortgage Revenue Refunding Bonds (Goodwin House, Inc.), 5.125% due 10/01/2042 3,197 2,500 Halifax County, Virginia, IDA, Exempt Facility Revenue Refunding Bonds (Old Dominion Electric Cooperative Project), AMT, 5.625% due 6/01/2028 (a) 2,679 5,000 Richmond, Virginia, Public Utilities Revenue Refunding Bonds, 5% due 1/15/2037 (g) 5,202 ----------------------------------------------------------------------------------------------------------------------------------- Washington - 12.3% 2,545 Bellevue, Washington, GO, Refunding, 5.25% due 12/01/2026 (b) 2,709 2,455 Bellevue, Washington, GO, Refunding, 5.25% due 12/01/2027 (b) 2,592 2,850 Bellevue, Washington, GO, Refunding, 5.25% due 12/01/2028 (b) 3,006 3,000 Bellevue, Washington, GO, Refunding, 5.25% due 12/01/2029 (b) 3,160 17,600 Bellevue, Washington, GO, Refunding, 5% due 12/01/2034 (b) 18,121 3,030 Chelan County, Washington, Public Utility District Number 001, Consolidated Revenue Bonds (Chelan Hydro System), AMT, Series A, 5.45% due 7/01/2037 (a) 3,144 6,000 Chelan County, Washington, Public Utility District Number 001, Consolidated Revenue Refunding Bonds (Chelan Hydro System), AMT, Series C, 5.65% due 7/01/2032 (b) 6,326 10,000 King County, Washington, School District Number 401 (Highline), GO, 5.25% due 12/01/2025 (g) 10,723 15,785 King County, Washington, Sewer Revenue Bonds, 5% due 1/01/2037 (g) 16,346 10,000 Radford Court Properties, Washington, Student Housing Revenue Bonds, 5.75% due 6/01/2032 (b) 10,545 1,720 Seattle, Washington, Drain and Wastewater Utility Revenue Bonds, 5.75% due 11/01/2009 (b)(f) 1,809 4,945 Skagit County, Washington, Public Hospital District, GO, Series A, 5.25% due 12/01/2025 (b) 5,237 5,450 Skagit County, Washington, Public Hospital District, GO, Series A, 5.25% due 12/01/2026 (b) 5,762 5,300 Tacoma, Washington, Regional Water Supply System, Water Revenue Bonds, 5% due 12/01/2032 (b) 5,424 7,250 Tacoma, Washington, Solid Waste Utility Revenue Refunding Bonds, Series B, 5.50% due 12/01/2007 (a)(f) 7,363 7,000 Washington State Health Care Facilities Authority Revenue Bonds (Providence Health System), Series A, 5.25% due 10/01/2021 (b) 7,248 12,035 Washington State, Motor Vehicle Fuel Tax, GO, Series B, 5% due 7/01/2031 (g) 12,499 ----------------------------------------------------------------------------------------------------------------------------------- West Virginia - 0.6% 5,925 Harrison County, West Virginia, County Commission for Solid Waste Disposal Revenue Bonds (Monongahela Power), AMT, Series C, 6.75% due 8/01/2024 (a) 5,938 ----------------------------------------------------------------------------------------------------------------------------------- Wisconsin - 0.4% 3,395 Wisconsin State Health and Educational Facilities Authority Revenue Bonds (SynergyHealth Inc.), 6% due 11/15/2032 3,589 ----------------------------------------------------------------------------------------------------------------------------------- Puerto Rico - 0.3% 20,000 Puerto Rico Sales Tax Financing Corporation, Sales Tax Revenue Refunding Bonds, Series A, 5.01% due 8/01/2043 (b)(p) 3,464 ----------------------------------------------------------------------------------------------------------------------------------- Total Municipal Bonds (Cost - $1,333,642) - 137.6% 11,370,477 ----------------------------------------------------------------------------------------------------------------------------------- BlackRock MuniYield Insured Fund, Inc. Schedule of Investments as of July 31, 2007 (Unaudited) (in Thousands) Face State Amount Municipal Bonds Held in Trust (j) Value ----------------------------------------------------------------------------------------------------------------------------------- California - 5.2% $ 14,900 California State, Various Purpose, GO, 5.50% due 11/01/2033 (b) $ 15,980 10,030 Gavilan, California, Joint Community College District, GO (Election of 2004), Series A, 5.50% due 8/01/2028 (a) 10,820 14,000 Port of Oakland, California, Revenue Bonds, AMT, Series K, 5.75% due 11/01/2021 (c) 14,561 9,460 Port of Oakland, California, Revenue Refunding Bonds, AMT, Series L, 5.375% due 11/01/2027 (c) 9,861 ----------------------------------------------------------------------------------------------------------------------------------- Florida - 1.1% 10,750 Miami-Dade County, Florida, Aviation Revenue Refunding Bonds (Miami International Airport), AMT, 5.375% due 10/01/2025 (c) 11,163 ----------------------------------------------------------------------------------------------------------------------------------- Georgia - 2.7% 26,500 Atlanta, Georgia, Airport General Revenue Refunding Bonds, AMT, Series A, 5.125% due 1/01/2030 (g) 27,140 ----------------------------------------------------------------------------------------------------------------------------------- Illinois - 8.2% 16,400 Chicago, Illinois, O'Hare International Airport, General Airport Revenue Refunding Bonds, Third Lien, AMT, Series C-2, 5.25% due 1/01/2030 (g) 16,949 16,680 Chicago, Illinois, O'Hare International Airport Revenue Bonds, Third Lien, AMT, Series B-2, 5.25% due 1/01/2027 (b) 17,266 26,230 Chicago, Illinois, O'Hare International Airport Revenue Bonds, Third Lien, AMT, Series B-2, 6% due 1/01/2027 (b) 28,892 17,200 Chicago, Illinois, O'Hare International Airport Revenue Bonds, Third Lien, AMT, Series B-2, 6% due 1/01/2029 (e) 18,935 ----------------------------------------------------------------------------------------------------------------------------------- Louisiana - 1.6% 15,000 Louisiana Public Facilities Authority, Mortgage Revenue Refunding Bonds (Baton Rouge General Medical Center Project), 5.25% due 7/01/2033 (b) 15,589 ----------------------------------------------------------------------------------------------------------------------------------- Michigan - 1.4% 8,000 Michigan State Strategic Fund, Limited Obligation Revenue Refunding Bonds (Detroit Edison Company Pollution Control Project), AMT, Series A, 5.50% due 6/01/2030 (e) 8,463 5,000 Michigan State Strategic Fund, Limited Obligation Revenue Refunding Bonds (Detroit Edison Company Pollution Control Project), AMT, Series C, 5.65% due 9/01/2029 (e) 5,236 ----------------------------------------------------------------------------------------------------------------------------------- Nevada - 1.3% 12,675 Clark County, Nevada, IDR (Southwest Gas Corporation Project), AMT, Series A, 5.25% due 7/01/2034 (a) 13,139 ----------------------------------------------------------------------------------------------------------------------------------- New Jersey - 3.2% 14,665 New Jersey EDA, Motor Vehicle Surcharge Revenue Bonds, Series A, 5.25% due 7/01/2031 (b) 15,501 15,000 New Jersey EDA, Motor Vehicle Surcharge Revenue Bonds, Series A, 5.25% due 7/01/2033 (b) 15,856 ----------------------------------------------------------------------------------------------------------------------------------- Oklahoma - 0.9% 8,680 Oklahoma State Industries Authority Revenue Refunding Bonds (Health System-Obligation Group), Series A, 5.75% due 8/15/2029 (b) 9,062 ----------------------------------------------------------------------------------------------------------------------------------- Pennsylvania - 1.7% 15,600 Pennsylvania State Turnpike Commission, Turnpike Revenue Bonds, Series A, 5.50% due 12/01/2031 (a) 16,898 ----------------------------------------------------------------------------------------------------------------------------------- Texas - 6.9% 21,000 Dallas-Fort Worth, Texas, International Airport Revenue Bonds, AMT, Series A, 5.50% due 11/01/2033 (b) 22,167 15,000 Dallas-Fort Worth, Texas, International Airport, Revenue Refunding and Improvement Bonds, AMT, Series A, 5.625% due 11/01/2026 (c) 15,686 30,000 Houston, Texas, Airport System Revenue Refunding Bonds, Sub-Lien, Series B, 5.50% due 7/01/2030 (g) 31,142 ----------------------------------------------------------------------------------------------------------------------------------- Washington - 2.1% 20,565 Port Seattle, Washington, Revenue Refunding Bonds, Series B, AMT, 5.20% due 7/01/2029 (b) 21,194 ----------------------------------------------------------------------------------------------------------------------------------- Total Municipal Bonds Held in Trust (Cost - $347,303) - 36.3% 361,500 ----------------------------------------------------------------------------------------------------------------------------------- Shares Held Short-Term Securities ----------------------------------------------------------------------------------------------------------------------------------- 28,800 Merrill Lynch Institutional Tax-Exempt Fund, 3.47% (m)(o) 28,800 ----------------------------------------------------------------------------------------------------------------------------------- Total Short-Term Securities (Cost - $28,800) - 2.9% 28,800 ----------------------------------------------------------------------------------------------------------------------------------- Total Investments (Cost - $1,709,745*) - 176.8% 1,760,777 Liabilities in Excess of Other Assets - (2.2%) (21,722) Liability for Trust Certificates, Including Interest Expense Payable - (17.3%) (172,700) Preferred Stock, at Redemption Value - (57.3%) (570,640) --------- Net Assets Applicable to Common Stock - 100.0% $ 995,715 ========== BlackRock MuniYield Insured Fund, Inc. Schedule of Investments as of July 31, 2007 (Unaudited) (in Thousands) * The cost and unrealized appreciation (depreciation) of investments, as of July 31, 2007, as computed for federal income tax purposes, were as follows: Aggregate cost $ 1,550,267 =========== Gross unrealized appreciation $ 40,944 Gross unrealized depreciation (2,099) ----------- Net unrealized appreciation $ 38,845 =========== (a) AMBAC Insured. (b) MBIA Insured. (c) FGIC Insured. (d) CIFG Insured. (e) XL Capital Insured. (f) Prerefunded. (g) FSA Insured. (h) Security may have a maturity of more than one year at time of issuance, but has variable rate and demand features that qualify it as a short-term security. The rate disclosed is that currently in effect. This rate changes periodically based upon prevailing market rates. (i) Escrowed to maturity. (j) Securities represent underlying bonds transferred to a separate securitization trust established in a tender option bond transaction in which the Fund may have acquired the residual interest certificates. These securities serve as collateral in a financing transaction. (k) FNMA/GNMA Collateralized. (l) FHLMC Collateralized. (m) Investments in companies considered to be an affiliate of the Fund, for purposes of Section 2(a)(3) of the Investment Company Act of 1940, were as follows: -------------------------------------------------------------------------- Net Dividend Affiliate Activity Income -------------------------------------------------------------------------- Merrill Lynch Institutional Tax-Exempt Fund 28,800 $ 149 -------------------------------------------------------------------------- (n) Assured Guaranty Insured. (o) Represents the current yield as of July 31, 2007. (p) Represents a zero coupon bond; the interest rate shown reflects the effective yield at the time of purchase. (q) Represents a step bond; the interest rate shown reflects the effective yield at the time of purchase. (r) FHA Insured. o Forward interest rate swaps outstanding as of July 31, 2007 were as follows: -------------------------------------------------------------------------- Notional Unrealized Amount Appreciation -------------------------------------------------------------------------- Pay a fixed rate of 3.697% and receive a floating rate based on 1-Week Bond Market Association Rate Broker, JPMorgan Chase Expires August 2017 $ 310,000 $ 4,759 -------------------------------------------------------------------------- Item 2 - Controls and Procedures 2(a) - The registrant's principal executive and principal financial officers or persons performing similar functions have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act")) are effective as of a date within 90 days of the filing of this report based on the evaluation of these controls and procedures required by Rule 30a-3(b) under the 1940 Act and Rule 13a-15(b) under the Securities and Exchange Act of 1934, as amended. 2(b) - There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting. Item 3 - Exhibits Certifications - Attached hereto Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. BlackRock MuniYield Insured Fund, Inc. By: /s/ Robert C. Doll, Jr. ----------------------------------- Robert C. Doll, Jr., Chief Executive Officer (principal executive officer) of BlackRock MuniYield Insured Fund, Inc. Date: September 20, 2007 Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated. By: /s/ Robert C. Doll, Jr. ----------------------------------- Robert C. Doll, Jr., Chief Executive Officer (principal executive officer) of BlackRock MuniYield Insured Fund, Inc. Date: September 20, 2007 By: /s/ Donald C. Burke ----------------------------------- Donald C. Burke, Chief Financial Officer (principal financial officer) of BlackRock MuniYield Insured Fund, Inc. Date: September 20, 2007