<TABLE> <S> <C>

<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE JOHN
HANCOCK VARIABLE SERIES TRUST I ANNUAL REPORT DATED DECEMBER 31, 1998 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<SERIES>
   <NUMBER> 22
   <NAME> SMALL/MID CAP CORE
<MULTIPLIER> 1000
       
<S>                             <C>
<PERIOD-TYPE>                   8-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-START>                             MAY-01-1998
<PERIOD-END>                               DEC-31-1998
<INVESTMENTS-AT-COST>                            4,681
<INVESTMENTS-AT-VALUE>                           4,945
<RECEIVABLES>                                        8
<ASSETS-OTHER>                                      64
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                                   5,017
<PAYABLE-FOR-SECURITIES>                             0
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                            2
<TOTAL-LIABILITIES>                                  2
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                         5,501
<SHARES-COMMON-STOCK>                              556
<SHARES-COMMON-PRIOR>                                0
<ACCUMULATED-NII-CURRENT>                            0
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                          (750)
<OVERDISTRIBUTION-GAINS>                             0
<ACCUM-APPREC-OR-DEPREC>                           264
<NET-ASSETS>                                     5,015
<DIVIDEND-INCOME>                                    4
<INTEREST-INCOME>                                   28
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                      32
<NET-INVESTMENT-INCOME>                              0
<REALIZED-GAINS-CURRENT>                         (750)
<APPREC-INCREASE-CURRENT>                          264
<NET-CHANGE-FROM-OPS>                            (486)
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                            0
<DISTRIBUTIONS-OF-GAINS>                             0
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                            636
<NUMBER-OF-SHARES-REDEEMED>                       (80)
<SHARES-REINVESTED>                                  0
<NET-CHANGE-IN-ASSETS>                           5,015
<ACCUMULATED-NII-PRIOR>                              0
<ACCUMULATED-GAINS-PRIOR>                            0
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                               24
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                    139
<AVERAGE-NET-ASSETS>                             4,561
<PER-SHARE-NAV-BEGIN>                            10.00
<PER-SHARE-NII>                                      0
<PER-SHARE-GAIN-APPREC>                         (0.98)
<PER-SHARE-DIVIDEND>                                 0
<PER-SHARE-DISTRIBUTIONS>                            0
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                               9.02
<EXPENSE-RATIO>                                   1.05
<AVG-DEBT-OUTSTANDING>                               0
<AVG-DEBT-PER-SHARE>                                 0
        

</TABLE>