<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000719269
<NAME> MFS SUNLIFE SERIES TRUST
<SERIES>
<NUMBER> 23
<NAME> MFS BOND SERIES
<MULTIPLIER> 1
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-1-2000
<PERIOD-END> JUN-30-2000
<INVESTMENTS-AT-COST> 59626766
<INVESTMENTS-AT-VALUE> 58604908
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<OTHER-ITEMS-LIABILITIES> 11803
<TOTAL-LIABILITIES> 2496744
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<SHARES-COMMON-STOCK> 5778561
<SHARES-COMMON-PRIOR> 5035082
<ACCUMULATED-NII-CURRENT> 1894698
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<OVERDISTRIBUTION-GAINS> (2038081)
<ACCUM-APPREC-OR-DEPREC> (1021858)
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<EXPENSES-NET> (186673)
<NET-INVESTMENT-INCOME> 1898228
<REALIZED-GAINS-CURRENT> (947323)
<APPREC-INCREASE-CURRENT> 798197
<NET-CHANGE-FROM-OPS> 1749102
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (2377758)
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<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1332155
<NUMBER-OF-SHARES-REDEEMED> (829583)
<SHARES-REINVESTED> 240907
<NET-CHANGE-IN-ASSETS> 6858589
<ACCUMULATED-NII-PRIOR> 2374228
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<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> (1090758)
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<AVERAGE-NET-ASSETS> 54262646
<PER-SHARE-NAV-BEGIN> 10.36
<PER-SHARE-NII> .36
<PER-SHARE-GAIN-APPREC> (.05)
<PER-SHARE-DIVIDEND> (.46)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 10.21
<EXPENSE-RATIO> .69
</TABLE>
