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<PAGE> PAGE 21
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<PAGE> PAGE 22
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<PAGE> PAGE 23
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<PAGE> PAGE 24
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<PAGE> PAGE 25
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<PAGE> PAGE 26
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<PAGE> PAGE 27
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<PAGE> PAGE 28
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<PAGE> PAGE 29
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<PAGE> PAGE 30
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<PAGE> PAGE 31
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<PAGE> PAGE 32
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<PAGE> PAGE 33
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<PAGE> PAGE 34
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<PAGE> PAGE 35
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<PAGE> PAGE 36
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<PAGE> PAGE 37
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<PAGE> PAGE 39
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<PAGE> PAGE 40
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074 A000800 737
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<PAGE> PAGE 41
074 K000800 48
074 L000800 81
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074 O000800 564
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075 A000800 0
075 B000800 29051
076 000800 0.00
SIGNATURE J. SPENCER WILLIAMS
TITLE CFO AND TREASURER
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMTION EXTRACTED FROM THE
REPORT TO SHAREHOLDERS OF MML SERIES INVESTMENT FUND FOR THE YEAR ENDED
DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000067160
<NAME> MML SERIES INVESTMENT FUND
<SERIES>
<NUMBER> 1
<NAME> MML EQUITY FUND
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> JAN-01-1999
<PERIOD-END> DEC-31-1999
<INVESTMENTS-AT-COST> 1,840,653,482
<INVESTMENTS-AT-VALUE> 2,835,096,514
<RECEIVABLES> 8,118,297
<ASSETS-OTHER> 11,673
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 2,843,226,484
<PAYABLE-FOR-SECURITIES> 6,098,388
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 88,972,763
<TOTAL-LIABILITIES> 95,071,151
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1,753,653,571
<SHARES-COMMON-STOCK> 75,176,572
<SHARES-COMMON-PRIOR> 74,956,036
<ACCUMULATED-NII-CURRENT> 58,730
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 994,443,032
<NET-ASSETS> 2,748,155,333
<DIVIDEND-INCOME> 59,479,611
<INTEREST-INCOME> 5,470,322
<OTHER-INCOME> 0
<EXPENSES-NET> 11,283,310
<NET-INVESTMENT-INCOME> 53,666,623
<REALIZED-GAINS-CURRENT> 32,212,209
<APPREC-INCREASE-CURRENT> (199,732,667)
<NET-CHANGE-FROM-OPS> (113,853,835)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (53,615,000)
<DISTRIBUTIONS-OF-GAINS> (32,524,676)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 4,812,759
<NUMBER-OF-SHARES-REDEEMED> (8,388,952)
<SHARES-REINVESTED> 3,796,729
<NET-CHANGE-IN-ASSETS> (189,952,131)
<ACCUMULATED-NII-PRIOR> 7,107
<ACCUMULATED-GAINS-PRIOR> 312,467
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 11,203,491
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 11,283,310
<AVERAGE-NET-ASSETS> 3,020,663,958
<PER-SHARE-NAV-BEGIN> 39.198
<PER-SHARE-NII> .713
<PER-SHARE-GAIN-APPREC> (2.210)
<PER-SHARE-DIVIDEND> (0.713)
<PER-SHARE-DISTRIBUTIONS> (0.433)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 36.555
<EXPENSE-RATIO> 0.37
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMTION EXTRACTED FROM THE
REPORT TO SHAREHOLDERS OF MML SERIES INVESTMENT FUND FOR THE YEAR ENDED
DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000067160
<NAME> MML SERIES INVESTMENT FUND
<SERIES>
<NUMBER> 2
<NAME> MML MONEY MARKET FUND
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> JAN-01-1999
<PERIOD-END> DEC-31-1999
<INVESTMENTS-AT-COST> 201,679,612
<INVESTMENTS-AT-VALUE> 201,679,612
<RECEIVABLES> 0
<ASSETS-OTHER> 1,843
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 201,681,455
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 1,111,544
<TOTAL-LIABILITIES> 1,111,544
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 200,567,821
<SHARES-COMMON-STOCK> 200,569,911
<SHARES-COMMON-PRIOR> 178,433,757
<ACCUMULATED-NII-CURRENT> 16,538
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (14,448)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 200,569,911
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 9,653,689
<OTHER-INCOME> 0
<EXPENSES-NET> 932,029
<NET-INVESTMENT-INCOME> 8,721,660
<REALIZED-GAINS-CURRENT> (2,451)
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 8,719,209
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (8,719,209)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 167,122,965
<NUMBER-OF-SHARES-REDEEMED> (153,549,427)
<SHARES-REINVESTED> 8,562,616
<NET-CHANGE-IN-ASSETS> 22,136,154
<ACCUMULATED-NII-PRIOR> 14,087
<ACCUMULATED-GAINS-PRIOR> (11,997)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 865,386
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 932,029
<AVERAGE-NET-ASSETS> 186,171,437
<PER-SHARE-NAV-BEGIN> 1.000
<PER-SHARE-NII> 0.047
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> (0.047)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.000
<EXPENSE-RATIO> 0.50
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REPORT TO SHAREHOLDERS OF MML SERIES INVESTMENT FUND FOR THE YEAR ENDED
DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000067160
<NAME> MML SERIES INVESTMENT FUND
<SERIES>
<NUMBER> 3
<NAME> MML MANAGED BOND FUND
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> JAN-01-1999
<PERIOD-END> DEC-31-1999
<INVESTMENTS-AT-COST> 250,093,767
<INVESTMENTS-AT-VALUE> 240,601,425
<RECEIVABLES> 3,196,020
<ASSETS-OTHER> 76,885
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 243,874,330
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 3,964,768
<TOTAL-LIABILITIES> 3,964,768
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 251,339,470
<SHARES-COMMON-STOCK> 20,663,404
<SHARES-COMMON-PRIOR> 20,173,153
<ACCUMULATED-NII-CURRENT> 49,970
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (1,987,536)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (9,492,342)
<NET-ASSETS> 239,909,562
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 17,066,150
<OTHER-INCOME> 0
<EXPENSES-NET> 1,274,414
<NET-INVESTMENT-INCOME> 15,791,736
<REALIZED-GAINS-CURRENT> (1,987,536)
<APPREC-INCREASE-CURRENT> (18,606,086)
<NET-CHANGE-FROM-OPS> (4,801,886)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (15,861,796)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3,342,080
<NUMBER-OF-SHARES-REDEEMED> (4,234,710)
<SHARES-REINVESTED> 1,382,881
<NET-CHANGE-IN-ASSETS> (14,199,118)
<ACCUMULATED-NII-PRIOR> 120,030
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 1,213,876
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1,274,414
<AVERAGE-NET-ASSETS> 255,282,325
<PER-SHARE-NAV-BEGIN> 12.596
<PER-SHARE-NII> 0.753
<PER-SHARE-GAIN-APPREC> (0.983)
<PER-SHARE-DIVIDEND> (0.756)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 11.610
<EXPENSE-RATIO> 0.50
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REPORT TO SHAREHOLDERS OF MML SERIES INVESTMENT FUND FOR THE YEAR ENDED
DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000067160
<NAME> MML SERIES INVESTMENT FUND
<SERIES>
<NUMBER> 4
<NAME> MML BLEND FUND
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> JAN-01-1999
<PERIOD-END> DEC-31-1999
<INVESTMENTS-AT-COST> 2,028,270,210
<INVESTMENTS-AT-VALUE> 2,699,558,752
<RECEIVABLES> 15,223,986
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> (16,466)
<TOTAL-ASSETS> 2,714,766,272
<PAYABLE-FOR-SECURITIES> 3,057,807
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 75,387,629
<TOTAL-LIABILITIES> 78,445,436
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1,964,981,742
<SHARES-COMMON-STOCK> 112,151,790
<SHARES-COMMON-PRIOR> 112,214,264
<ACCUMULATED-NII-CURRENT> 50,552
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 671,288,542
<NET-ASSETS> 2,636,320,836
<DIVIDEND-INCOME> 34,401,978
<INTEREST-INCOME> 73,016,528
<OTHER-INCOME> 0
<EXPENSES-NET> 10,881,795
<NET-INVESTMENT-INCOME> 96,536,711
<REALIZED-GAINS-CURRENT> 49,460,859
<APPREC-INCREASE-CURRENT> (178,772,580)
<NET-CHANGE-FROM-OPS> (32,775,010)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (96,568,344)
<DISTRIBUTIONS-OF-GAINS> (49,654,848)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 4,777,625
<NUMBER-OF-SHARES-REDEEMED> (14,823,643)
<SHARES-REINVESTED> 9,983,544
<NET-CHANGE-IN-ASSETS> (178,368,074)
<ACCUMULATED-NII-PRIOR> 82,185
<ACCUMULATED-GAINS-PRIOR> 193,989
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 10,793,795
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 10,881,795
<AVERAGE-NET-ASSETS> 2,886,885,615
<PER-SHARE-NAV-BEGIN> 25.083
<PER-SHARE-NII> 0.837
<PER-SHARE-GAIN-APPREC> (1.133)
<PER-SHARE-DIVIDEND> (0.837)
<PER-SHARE-DISTRIBUTIONS> (0.443)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 23.507
<EXPENSE-RATIO> 0.38
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REPORT TO SHAREHOLDERS OF MML SERIES INVESTMENT FUND FOR THE YEAR ENDED
DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000067160
<NAME> MML SERIES INVESTMENT FUND
<SERIES>
<NUMBER> 5
<NAME> MML EQUITY INDEX FUND
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> JAN-01-1999
<PERIOD-END> DEC-31-1999
<INVESTMENTS-AT-COST> 74,528,185
<INVESTMENTS-AT-VALUE> 96,217,252
<RECEIVABLES> 132,746
<ASSETS-OTHER> 30,813
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 96,380,811
<PAYABLE-FOR-SECURITIES> 57,157
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 1,274,393
<TOTAL-LIABILITIES> 1,331,550
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 73,374,944
<SHARES-COMMON-STOCK> 5,242,380
<SHARES-COMMON-PRIOR> 2,363,757
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> (82,710)
<ACCUM-APPREC-OR-DEPREC> 21,757,027
<NET-ASSETS> 95,049,261
<DIVIDEND-INCOME> 659,985
<INTEREST-INCOME> 96,905
<OTHER-INCOME> 0
<EXPENSES-NET> 267,877
<NET-INVESTMENT-INCOME> 489,013
<REALIZED-GAINS-CURRENT> 581,500
<APPREC-INCREASE-CURRENT> 10,753,807
<NET-CHANGE-FROM-OPS> 11,824,320
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (491,028)
<DISTRIBUTIONS-OF-GAINS> (686,989)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3,612,656
<NUMBER-OF-SHARES-REDEEMED> (736,879)
<SHARES-REINVESTED> 2,846
<NET-CHANGE-IN-ASSETS> 58,979,984
<ACCUMULATED-NII-PRIOR> 682
<ACCUMULATED-GAINS-PRIOR> 22,670
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 212,438
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 267,877
<AVERAGE-NET-ASSETS> 53,122,330
<PER-SHARE-NAV-BEGIN> 15.260
<PER-SHARE-NII> 0.093
<PER-SHARE-GAIN-APPREC> 3.006
<PER-SHARE-DIVIDEND> (0.094)
<PER-SHARE-DISTRIBUTIONS> (0.135)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 18.130
<EXPENSE-RATIO> 0.50
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REPORT TO SHAREHOLDERS OF MML SERIES INVESTMENT FUND FOR THE YEAR ENDED
DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000067160
<NAME> MML SERIES INVESTMENT FUND
<SERIES>
<NUMBER> 6
<NAME> MML SMALL CAP VALUE EQUITY FUND
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> JAN-01-1999
<PERIOD-END> DEC-31-1999
<INVESTMENTS-AT-COST> 14,472,746
<INVESTMENTS-AT-VALUE> 13,835,690
<RECEIVABLES> 104,164
<ASSETS-OTHER> 6,420,914
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 20,360,768
<PAYABLE-FOR-SECURITIES> 4,776
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 218,895
<TOTAL-LIABILITIES> 223,671
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 21,675,682
<SHARES-COMMON-STOCK> 2,415,458
<SHARES-COMMON-PRIOR> 1,229,502
<ACCUMULATED-NII-CURRENT> 1,312
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> (902,841)
<ACCUM-APPREC-OR-DEPREC> (637,056)
<NET-ASSETS> 20,137,097
<DIVIDEND-INCOME> 139,556
<INTEREST-INCOME> 130,040
<OTHER-INCOME> 0
<EXPENSES-NET> 107,370
<NET-INVESTMENT-INCOME> 162,226
<REALIZED-GAINS-CURRENT> (626,497)
<APPREC-INCREASE-CURRENT> 482,379
<NET-CHANGE-FROM-OPS> 18,108
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (160,000)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1,355,252
<NUMBER-OF-SHARES-REDEEMED> (173,705)
<SHARES-REINVESTED> 4,409
<NET-CHANGE-IN-ASSETS> 9,694,913
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> (914)
<OVERDIST-NET-GAINS-PRIOR> (276,344)
<GROSS-ADVISORY-FEES> 91,822
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 153,741
<AVERAGE-NET-ASSETS> 14,303,637
<PER-SHARE-NAV-BEGIN> 8.493
<PER-SHARE-NII> 0.068
<PER-SHARE-GAIN-APPREC> (0.158)
<PER-SHARE-DIVIDEND> (0.066)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 8.337
<EXPENSE-RATIO> 0.75
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REPORT TO SHAREHOLDERS OF MML SERIES INVESTMENT FUND FOR THE YEAR ENDED
DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000067160
<NAME> MML SERIES INVESTMENT FUND
<SERIES>
<NUMBER> 7
<NAME> MML SMALL CAP GROWTH EQUITY FUND
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> MAY-03-1999
<PERIOD-END> DEC-31-1999
<INVESTMENTS-AT-COST> 31,316,634
<INVESTMENTS-AT-VALUE> 45,458,451
<RECEIVABLES> 166,303
<ASSETS-OTHER> 3,623,311
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 49,248,065
<PAYABLE-FOR-SECURITIES> 6,000
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 1,365,433
<TOTAL-LIABILITIES> 1,371,433
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 30,763,436
<SHARES-COMMON-STOCK> 2,964,471
<SHARES-COMMON-PRIOR> 0
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 2,971,379
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 14,141,817
<NET-ASSETS> 47,876,632
<DIVIDEND-INCOME> 41,435
<INTEREST-INCOME> 180,694
<OTHER-INCOME> 0
<EXPENSES-NET> 245,347
<NET-INVESTMENT-INCOME> (23,218)
<REALIZED-GAINS-CURRENT> 4,231,189
<APPREC-INCREASE-CURRENT> 14,141,817
<NET-CHANGE-FROM-OPS> 18,349,788
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (1,236,592)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 2,994,549
<NUMBER-OF-SHARES-REDEEMED> (30,078)
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> 47,876,632
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 222,489
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 296,923
<AVERAGE-NET-ASSETS> 31,087,273
<PER-SHARE-NAV-BEGIN> 10.000
<PER-SHARE-NII> (0.008)
<PER-SHARE-GAIN-APPREC> 6.576
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.418)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 16.150
<EXPENSE-RATIO> 0.79
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
REPORT TO SHAREHOLDERS OF MML SERIES INVESTMENT FUND FOR THE YEAR ENDED
DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000067160
<NAME> MML SERIES INVESTMENT FUND
<SERIES>
<NUMBER> 8
<NAME> MML GROWTH EQUITY FUND
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-START> MAY-03-1999
<PERIOD-END> DEC-31-1999
<INVESTMENTS-AT-COST> 31,199,560
<INVESTMENTS-AT-VALUE> 38,994,820
<RECEIVABLES> 413,672
<ASSETS-OTHER> 737,377
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 40,145,869
<PAYABLE-FOR-SECURITIES> 564,290
<SENIOR-LONG-TERM-DEBT> 0
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<PAID-IN-CAPITAL-COMMON> 30,847,417
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</TABLE>
EXHIBIT INDEX TO FORM N-SAR
OF MML SERIES INVESTMENT FUND
FOR THE PERIOD ENDED DECEMBER 31, 1999
Exhibit No. Description
77B Accountant's report on internal control
77K Changes in Registrant's certifying accountant
77O Transactions effected pursuant to Rule 10f-3
For Period Ending 12/31/99
File No. 811-2224
77B Accountant's report on internal control
INDEPENDENT AUDITORS' REPORT
The Board of Trustees,
MML Series Investment Fund:
In planning and performing our audits of the financial statements of MML
Series Investment Fund (the "Trust") for the year ended December 31, 1999
(on which we have issued our reports dated February 1, 2000 and February 8,
2000), we considered its internal control, including control activities for
safeguarding securities, in order to determine our auditing procedures for
the purpose of expressing our opinion on the financial statements and to
comply with the requirements of Form N-SAR, and not to provide assurance on
the Trust's internal control.
The management of the Trust is responsible for establishing and maintaining
internal control. In fulfilling this responsibility, estimates and judgments
by management are required to assess the expected benefits and related costs
of controls. Generally, controls that are relevant to an audit pertain to
the entity's objective of preparing financial statements for external
purposes that are fairly presented in conformity with generally accepted
accounting principles. Those controls include the safeguarding of assets
against unauthorized acquisition, use, or disposition.
Because of inherent limitations in any internal control, misstatements due to
error or fraud may occur and not be detected. Also, projections of any
evaluation of internal control to future periods are subject to the risk that
the internal control may become inadequate because of changes in conditions,
or that the degree of compliance with policies or procedures may deteriorate.
Our consideration of the Trust's internal control would not necessarily
disclose all matters in the internal control that might be material
weaknesses under standards established by the American Institute of Certified
Public Accountants. A material weakness is a condition in which the design
or operation of one or more of the internal control components does not
reduce to a relatively low level the risk that misstatements caused by error
or fraud in amounts that would be material in relation to the financial
statements being audited may occur and not be detected within a timely period
by employees in the normal course of performing their assigned functions.
However, we noted no matters involving the Trust's internal control and its
operation, including controls for safeguarding securities, that we consider
to be material weaknesses as defined above as of December 31, 1999.
This report is intended solely for the information and use of management, the
Board of Trustees of the Trust, and the Securities and Exchange Commission
and is not intended to be and should not be used by anyone other than these
specified parties.
/s/ Deloitte & Touche LLP
February 8, 2000
For Period Ending 12/31/99
File No. 811-2224
Item 77K: Changes in Registrant's certifying accountant
Registrant's Board of Trustees dismissed PricewaterhouseCoopers LLP ("PwC") as
its principal accountant, effective July 22, 1999. Registrant's Audit
Committee recommended engaging Deloitte & Touche LLP as the principal
accountant to audit the Funds' financial statements for fiscal year 1999.
The Board of Trustees approved the appointment of Deloitte & Touche LLP at
a special meeting held on March 26, 1999.
For fiscal years 1997 and 1998, and during the period prior to PwC's dismissal,
Registrant Trust and PwC have not had any disagreements on any matter of
accounting principles or practices, financial statement disclosures, or
auditing scope or procedure, that either (1) have not been resolved to
PwC's satisfaction and (2) or, if not resolved to PwC's satisfaction,
would have caused it to make a reference to the subject matter of the
disagreement in connection with its report. Moreover, PwC's report on the
Funds' financial statements for the fiscal years 1997 and 1998 did not
contain an adverse opinion or a disclaimer of opinion, and was not
qualified or modified as to uncertainty, audit scope or accounting
principles.
For Period Ending 12/31/99
File No. 811-2224
Item 770. Transactions Effected Pursuant to Rule 10f-3
MML Small Cap Growth Equity Fund (Series 7)
On September 27, 1999, Registrant purchased 475 shares issued by Foundry
Networks at a price of $25 per share, amounting to a $11,875 aggregate purchase
price. J.P. Morgan Securities Inc., an affiliate of J.P. Morgan Investment
Management Inc., one of the Fund's (Series 7) sub-advisers, participated in the
underwriting syndicate. Deutsche Morgan Grenfell was the broker from whom the
Fund purchased shares.
On September 27, 1999, Registrant purchased 600 shares issued by Foundry
Networks at a price of $25 per share, amounting to a $15,600 aggregate purchase
price. J.P. Morgan & Co., an affiliate of J.P. Morgan Investment Management
Inc., participated in the underwriting syndicate. Deutsche Bank Securities
was the broker from whom the Fund purchased shares.
On October 7, 1999, Registrant purchased 1,100 shares issued by Illuminet at a
price of $19 per share, amounting to a $20,900 aggregate purchase price.
Jefferies & Co., Inc., an entity that may be deemed an affiliate of the Fund,
participated in the underwriting syndicate. Morgan Stanley & Co., Inc. was the
broker from whom the Fund purchased shares.
On October 18, 1999, Registrant purchased 3,000 shares issued by Martha Stewart
Living at $18 per share, amounting to a $54,000 aggregate purchase price.
Advest, Inc., an entity that may be deemed an affiliate of the Fund,
participate in the underwriting syndicate. Morgan Stanley & Co., Inc. was
the broker from whom the Fund purchased shares.
On November 11, 1999, Registrant purchased 400 shares issued by Finisar Corp.
at a price of $19 per share, amounting to a $7,600 purchase price. J.P.
Morgan Securities participated in the underwriting syndicate. Merrill Lynch
was the broker from whom the Fund purchased the shares.
On November 11, 1999, Registrant purchased 3,000 shares issued by Finisar Corp.
at a price of $19 per share, amounting to $57,000 aggregate purchase price.
J.P. Morgan Securities participated in the underwriting syndicate. Merrill
Lynch was the broker from whom the Fund purchased shares.
On December 9, 1999, Registrant purchased 900 shares issued by Freemarkets at a
price of $48 per share, amounting to a $43,200 aggregate purchase price.
Advest, Inc. participated in the underwriting syndicate. Morgan Stanley & Co.,
Inc. was the broker from whom the Fund purchased shares.
Richard G. Dooley, a Trustee of Registrant, is a director of Jefferies Group,
Inc., the parent of Jefferies & Co. and Advest, Inc. In addition, J.P. Morgan
is considered an affiliated underwriter since a related entity is the sub-
adviser to the MML Small Cap Growth Equity Fund, Series 7 of Registrant.
To the extent such offerings might be deemed to be underwritten public
offerings, Registrant claims an exemption from the provisions of Section 10(f)
of the Investment Company Act of 1940, as amended, (the "Act") on the basis
that, with respect to this purchase, Registrant has complied with the
provisions of Rule 10f-3 promulgated under the Act. Registrant's Board of
Trustees has adopted procedures, pursuant to which such purchases may be
effected. Such procedures are reasonably designed to provide for the
conditions set forth in subsections (a) through (g) of Rule 10f-3.
Registrant will preserve a record of this transaction for a period of six years
from the end of the fiscal year in which the transaction occurred, the first
two years in an easily accessible place.
