<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information
extracted from MML
form N-SAR for the period ended June 30, 2000
and is qualified in its entirety by reference to
such financial statements.
</LEGEND>
<SERIES>
<NUMBER> 51
<NAME> Equity Index Fund, Class I
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-END> JUN-30-2000
<INVESTMENTS-AT-COST> 127,624,231
<INVESTMENTS-AT-VALUE> 149,030,620
<RECEIVABLES> 264,590
<ASSETS-OTHER> 2,996,559
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 152,291,769
<PAYABLE-FOR-SECURITIES> 75,559
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 81,890
<TOTAL-LIABILITIES> 157,449
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 130,584,902
<SHARES-COMMON-STOCK> 4,147,055
<SHARES-COMMON-PRIOR> 5,242,380
<ACCUMULATED-NII-CURRENT> 284,814
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (36,683)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 21,301,287
<NET-ASSETS> 152,134,320
<DIVIDEND-INCOME> 657,759
<INTEREST-INCOME> 172,031
<OTHER-INCOME> 0
<EXPENSES-NET> 239,070
<NET-INVESTMENT-INCOME> 590,720
<REALIZED-GAINS-CURRENT> 46,027
<APPREC-INCREASE-CURRENT> (455,740)
<NET-CHANGE-FROM-OPS> 181,007
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 134,560
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3,272,393
<NUMBER-OF-SHARES-REDEEMED> 4,437,730
<SHARES-REINVESTED> 70,012
<NET-CHANGE-IN-ASSETS> 57,085,059
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> (82,710)
<GROSS-ADVISORY-FEES> 170,330
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 255,905
<AVERAGE-NET-ASSETS> 120,416,921
<PER-SHARE-NAV-BEGIN> 18.13
<PER-SHARE-NII> 0.11
<PER-SHARE-GAIN-APPREC> (0.23)
<PER-SHARE-DIVIDEND> (0.04)
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 17.97
<EXPENSE-RATIO> 0.45
</TABLE>
