<PAGE> PAGE 1
000 A000000 06/30/2000
000 C000000 0000779128
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 U
001 A000000 DREYFUS 100% U.S. TREASURY MONEY MARKET FUND
001 B000000 811-4430
001 C000000 2129226833
002 A000000 200 PARK AVENUE
002 B000000 NEW YORK
002 C000000 NY
002 D010000 10166
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
011 A000001 DREYFUS SERVICE CORPORATION
011 B000001 8-13801
011 C010001 NEW YORK
011 C020001 NY
011 C030001 10166
015 A000001 THE BANK OF NEW YORK
015 B000001 C
015 C010001 NEW YORK
015 C020001 NY
015 C030001 10286
015 E010001 X
018 000000 Y
019 A000000 Y
019 B000000 172
019 C000000 DREYFUSFAM
022 A000001 DONALDSON, LUFKIN, & JENRETTE SECURITIES CORP
022 B000001 13-2741729
022 C000001 769400
022 D000001 310310
022 A000002 UBS AG
022 B000002 13-2932996
022 C000002 469166
022 D000002 421413
022 A000003 ABN AMRO SECURITIES (USA) INC.
022 B000003 13-3227945
022 C000003 350417
022 D000003 385242
022 A000004 HSBC JAMES CAPEL SECURITIES, INC.
022 B000004 13-2650272
<PAGE> PAGE 2
022 C000004 346673
022 D000004 198461
022 A000005 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
022 B000005 13-5674085
022 C000005 296942
022 D000005 149326
022 A000006 GOLDMAN, SACHS & CO.
022 B000006 13-5108880
022 C000006 106372
022 D000006 231867
022 A000007 BARCLAYS DE ZOETTE WEDD SECURITIES, INC.
022 B000007 13-3551367
022 C000007 220747
022 D000007 50767
022 A000008 MORGAN STANLEY DEAN WITTER & CO.
022 B000008 13-2655998
022 C000008 98661
022 D000008 99758
022 A000009 FIRST TENNESSEE
022 B000009 62-0201385
022 C000009 197755
022 D000009 0
022 A000010 PRUDENTIAL SECURITIES INCORPORATED
022 B000010 22-2347336
022 C000010 148804
022 D000010 0
023 C000000 3104028
023 D000000 1848329
028 A010000 130231
028 A020000 3979
028 A030000 0
028 A040000 154927
028 B010000 78154
028 B020000 3825
028 B030000 0
028 B040000 78100
028 C010000 105360
028 C020000 4372
028 C030000 0
028 C040000 89967
028 D010000 81641
028 D020000 3908
028 D030000 0
028 D040000 143465
028 E010000 78364
028 E020000 4568
028 E030000 0
028 E040000 90793
028 F010000 73862
028 F020000 4249
028 F030000 0
<PAGE> PAGE 3
028 F040000 98786
028 G010000 547612
028 G020000 24901
028 G030000 0
028 G040000 656038
028 H000000 0
062 A000000 Y
062 B000000 98.6
062 C000000 0.0
062 D000000 0.0
062 E000000 0.0
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 0.0
062 P000000 0.0
062 Q000000 0.0
062 R000000 0.0
063 A000000 81
063 B000000 0.0
064 A000000 N
071 A000000 0
071 B000000 0
071 C000000 0
071 D000000 0
072 A000000 6
072 B000000 29936
072 C000000 0
072 D000000 0
072 E000000 0
072 F000000 2672
072 G000000 0
072 H000000 0
072 I000000 923
072 J000000 41
072 K000000 0
072 L000000 25
072 M000000 36
072 N000000 27
072 O000000 1
072 P000000 0
072 Q000000 0
072 R000000 14
072 S000000 5
072 T000000 0
<PAGE> PAGE 4
072 U000000 0
072 V000000 0
072 W000000 5
072 X000000 3749
072 Y000000 0
072 Z000000 26187
072AA000000 447
072BB000000 52
072CC010000 0
072CC020000 0
072DD010000 26187
072DD020000 0
072EE000000 0
073 A010000 0.0244
073 A020000 0.0000
073 B000000 0.0000
073 C000000 0.0000
074 A000000 0
074 B000000 0
074 C000000 1008755
074 D000000 0
074 E000000 0
074 F000000 0
074 G000000 0
074 H000000 0
074 I000000 0
074 J000000 0
074 K000000 14985
074 L000000 0
074 M000000 43
074 N000000 1023783
074 O000000 0
074 P000000 454
074 Q000000 0
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 332
074 S000000 0
074 T000000 1022997
074 U010000 1022721
074 U020000 0
074 V010000 1.00
074 V020000 0.00
074 W000000 1.0003
074 X000000 20657
074 Y000000 0
075 A000000 1074747
075 B000000 0
076 000000 0.00
077 A000000 Y
<PAGE> PAGE 5
077 Q010000 Y
SIGNATURE MICHAEL A. ROSENBERG
TITLE SECRETARY
