PAGE 1
000 A000000 04/30/2007
000 C000000 0000883412
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 A
001 A000000 BLACKROCK MUNIYIELD INSURED FUND, INC.
001 B000000 811-06540
001 C000000 6092822800
002 A000000 P.O. BOX 9011
002 B000000 PRINCETON
002 C000000 NJ
002 D010000 08543
002 D020000 9011
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
007 C010100 1
007 C010200 2
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
007 C011100 11
007 C011200 12
007 C011300 13
007 C011400 14
007 C011500 15
007 C011600 16
007 C011700 17
007 C011800 18
007 C011900 19
007 C012000 20
008 A000001 BLACKROCK ADVISORS, LLC
008 B000001 A
008 C000001 801-47710
008 D010001 WILMINGTON
008 D020001 DE
008 D030001 19809
008 A000002 BLACKROCK INVESTMENT MANAGEMENT, LLC
008 B000002 S
PAGE 2
008 C000002 801-56972
008 D010002 PLAINSBORO
008 D020002 NJ
008 D030002 08536
011 A000001 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
011 B000001 8-7221
011 C010001 NEW YORK
011 C020001 NY
011 C030001 10281
011 C040001 1201
012 A000001 COMPUTERSHARE TRUST COMPANY, N.A. (COMMOM)
012 B000001 85-11340
012 C010001 PROVIDENCE
012 C020001 RI
012 C030001 02940
012 C040001 3010
012 A000002 THE BANK OF NEW YORK (PREFERRED)
012 B000002 85-05006
012 C010002 NEW YORK
012 C020002 NY
012 C030002 10286
013 A000001 DELOITTE & TOUCHE LLP
013 B010001 PRINCETON
013 B020001 NJ
013 B030001 08540
014 A000001 MLPF&S AND OTHER ML BROKER\DEALER AFFILIATES
014 B000001 8-7221
014 A000002 BLACKROCK INVESTMENTS, INC.
014 B000002 8-048436
014 A000003 NORTHERN FUNDS DISTRIBUTORS, LLC
014 B000003 8-051242
014 A000004 PNC CAPITAL MARKETS, LLC
014 B000004 8-032493
014 A000005 J.J.B. HILLIARD W.L. LYONS, INC.
014 B000005 8-033133
014 A000006 PFPC DISTRIBUTORS, INC.
014 B000006 8-045467
014 A000007 MGI FUNDS DISTRIBUTORS, INC.
014 B000007 8-046960
014 A000008 ABN AMRO DISTRIBUTION SERVICES, INC.
014 B000008 8-052396
014 A000009 BLACKROCK DISTRIBUTORS, INC.
014 B000009 8-048775
014 A000010 PERSIMMON SECURITIES, INC.
014 B000010 8-053071
014 A000011 PNC INVESTMENTS LLC
014 B000011 8-066195
014 A000012 STATE STREET RESEARCH INVEST SERV, INC.
014 B000012 8-035442
015 A000001 STATE STREET BANK AND TRUST COMPANY
015 B000001 C
PAGE 3
015 C010001 BOSTON
015 C020001 MA
015 C030001 02101
015 E010001 X
015 A000002 THE BANK OF NEW YORK
015 B000002 S
015 C010002 NEW YORK
015 C020002 NY
015 C030002 10286
015 E010002 X
015 A000003 BANKERS TRUST COMPANY
015 B000003 S
015 C010003 NEW YORK
015 C020003 NY
015 C030003 10006
015 E010003 X
015 A000004 J.P. MORGAN CHASE BANK
015 B000004 S
015 C010004 NEW YORK
015 C020004 NY
015 C030004 10017
015 E010004 X
015 A000005 CUSTODIAL TRUST CO.
015 B000005 S
015 C010005 NEW YORK
015 C020005 NY
015 C030005 10167
015 E010005 X
015 A000006 MORGAN GUARANTY TRUST CO. OF NEW YORK
015 B000006 S
015 C010006 NEW YORK
015 C020006 NY
015 C030006 10260
015 E010006 X
018 000000 Y
019 A000000 Y
019 B000000 172
019 C000000 BLACKROCKC
020 C000001 0
020 C000002 0
020 C000003 0
020 C000004 0
020 C000005 0
020 C000006 0
020 C000007 0
020 C000008 0
020 C000009 0
020 C000010 0
021 000000 0
022 A000001 GOLDMAN, SACHS & CO.
022 B000001 13-5108880
PAGE 4
022 C000001 490439
022 D000001 390747
022 A000002 MERRILL LYNCH INSTITUTIONAL TAX-EXEMPT FUND
022 B000002 22-2509978
022 C000002 191900
022 D000002 191900
022 A000003 MORGAN STANLEY
022 B000003 13-2655998
022 C000003 139235
022 D000003 97432
022 A000004 CITIGROUP GLOBAL MARKETS, INC.
022 B000004 11-2418191
022 C000004 65771
022 D000004 168588
022 A000005 J.P. MORGAN SECURITIES INC.
022 B000005 13-3224016
022 C000005 68697
022 D000005 136359
022 A000006 UBS SECURITIES LLC
022 B000006 13-3873456
022 C000006 94543
022 D000006 92772
022 A000007 LEHMAN BROTHERS INC.
022 B000007 13-2518466
022 C000007 103237
022 D000007 43628
022 A000008 BEAR, STEARNS & CO. INC.
022 B000008 13-3299429
022 C000008 57054
022 D000008 44816
022 A000009 MORGAN KEEGAN & COMPANY, INC.
022 B000009 64-0474907
022 C000009 45670
022 D000009 55205
022 A000010 BANC OF AMERICA SECURITIES LLC
022 B000010 56-2058405
022 C000010 31448
022 D000010 16024
023 C000000 1436127
023 D000000 1383133
024 000000 N
026 A000000 N
026 B000000 Y
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 N
PAGE 5
045 000000 Y
046 000000 N
047 000000 Y
048 000000 0.500
048 A010000 0
048 A020000 0.000
048 B010000 0
048 B020000 0.000
048 C010000 0
048 C020000 0.000
048 D010000 0
048 D020000 0.000
048 E010000 0
048 E020000 0.000
048 F010000 0
048 F020000 0.000
048 G010000 0
048 G020000 0.000
048 H010000 0
048 H020000 0.000
048 I010000 0
048 I020000 0.000
048 J010000 0
048 J020000 0.000
048 K010000 0
048 K020000 0.000
049 000000 N
050 000000 N
051 000000 N
052 000000 N
053 A000000 N
054 A000000 Y
054 B000000 Y
054 C000000 N
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 N
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 N
054 M000000 Y
054 N000000 N
055 A000000 N
055 B000000 N
056 000000 Y
057 000000 N
058 A000000 N
059 000000 Y
PAGE 6
060 A000000 N
060 B000000 N
061 000000 0
062 A000000 Y
062 B000000 0.0
062 C000000 0.0
062 D000000 0.0
062 E000000 2.1
062 F000000 0.0
062 G000000 0.0
062 H000000 0.0
062 I000000 0.0
062 J000000 0.0
062 K000000 0.0
062 L000000 0.0
062 M000000 0.0
062 N000000 0.0
062 O000000 174.4
062 P000000 0.0
062 Q000000 0.0
062 R000000 0.0
063 A000000 0
063 B000000 23.8
064 A000000 Y
064 B000000 N
066 A000000 N
067 000000 N
068 A000000 N
068 B000000 N
069 000000 N
070 A010000 Y
070 A020000 N
070 B010000 N
070 B020000 N
070 C010000 Y
070 C020000 N
070 D010000 N
070 D020000 N
070 E010000 Y
070 E020000 N
070 F010000 N
070 F020000 N
070 G010000 Y
070 G020000 N
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 N
070 J020000 N
070 K010000 Y
PAGE 7
070 K020000 Y
070 L010000 N
070 L020000 N
070 M010000 N
070 M020000 N
070 N010000 Y
070 N020000 N
070 O010000 Y
070 O020000 N
070 P010000 Y
070 P020000 N
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000 809963
071 B000000 762863
071 C000000 1774316
071 D000000 43
072 A000000 6
072 B000000 40663
072 C000000 71
072 D000000 0
072 E000000 0
072 F000000 3967
072 G000000 184
072 H000000 0
072 I000000 82
072 J000000 39
072 K000000 0
072 L000000 38
072 M000000 26
072 N000000 0
072 O000000 0
072 P000000 3432
072 Q000000 0
072 R000000 23
072 S000000 12
072 T000000 0
072 U000000 0
072 V000000 0
072 W000000 796
072 X000000 8599
072 Y000000 4
072 Z000000 32139
072AA000000 16978
072BB000000 3745
072CC010000 0
072CC020000 18315
072DD010000 22748
072DD020000 0
PAGE 8
072EE000000 0
073 A010000 0.3380
073 A020000 0.0000
073 B000000 0.0000
073 C000000 0.0000
074 A000000 52
074 B000000 0
074 C000000 21300
074 D000000 1786858
074 E000000 0
074 F000000 0
074 G000000 0
074 H000000 0
074 I000000 0
074 J000000 10753
074 K000000 0
074 L000000 25200
074 M000000 196
074 N000000 1844359
074 O000000 55178
074 P000000 671
074 Q000000 0
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 193646
074 S000000 570560
074 T000000 1024304
074 U010000 67303
074 U020000 0
074 V010000 15.22
074 V020000 0.00
074 W000000 0.0000
074 X000000 26608
074 Y000000 602958
075 A000000 0
075 B000000 1599792
076 000000 14.33
077 A000000 Y
077 O000000 Y
078 000000 N
086 A010000 0
086 A020000 0
086 B010000 0
086 B020000 0
086 C010000 0
086 C020000 0
086 D010000 0
086 D020000 0
086 E010000 0
086 E020000 0
PAGE 9
086 F010000 0
086 F020000 0
087 A010000 COMMON STOCK
087 A020000 09254E103
087 A030000 MYI
087 B010000 PREFERRED STOCK
088 A000000 N
088 B000000 N
088 C000000 N
088 D000000 Y
SIGNATURE DONALD C. BURKE
TITLE TREASURER