<TABLE> <S> <C>

<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE JOHN
HANCOCK VARIABLE SERIES TRUST I SEMIANNUAL REPORT DATED JUNE 30, 1999 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<SERIES>
   <NUMBER> 23
   <NAME> HIGH YIELD BOND
<MULTIPLIER> 1000

<S>                             <C>
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               JUN-30-1999
<INVESTMENTS-AT-COST>                           17,703
<INVESTMENTS-AT-VALUE>                          17,137
<RECEIVABLES>                                      376
<ASSETS-OTHER>                                       0
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                                  17,513
<PAYABLE-FOR-SECURITIES>                            33
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                           12
<TOTAL-LIABILITIES>                                 45
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                        18,235
<SHARES-COMMON-STOCK>                            1,909
<SHARES-COMMON-PRIOR>                                0
<ACCUMULATED-NII-CURRENT>                            0
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                             24
<OVERDISTRIBUTION-GAINS>                             0
<ACCUM-APPREC-OR-DEPREC>                            24
<NET-ASSETS>                                    17,468
<DIVIDEND-INCOME>                                    6
<INTEREST-INCOME>                                  700
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                      69
<NET-INVESTMENT-INCOME>                            637
<REALIZED-GAINS-CURRENT>                            24
<APPREC-INCREASE-CURRENT>                        (225)
<NET-CHANGE-FROM-OPS>                              436
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                        (637)
<DISTRIBUTIONS-OF-GAINS>                             0
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                            657
<NUMBER-OF-SHARES-REDEEMED>                      (418)
<SHARES-REINVESTED>                                 68
<NET-CHANGE-IN-ASSETS>                           2,679
<ACCUMULATED-NII-PRIOR>                              0
<ACCUMULATED-GAINS-PRIOR>                            0
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                               53
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                    103
<AVERAGE-NET-ASSETS>                                 0
<PER-SHARE-NAV-BEGIN>                             9.23
<PER-SHARE-NII>                                    .36
<PER-SHARE-GAIN-APPREC>                          (.08)
<PER-SHARE-DIVIDEND>                             (.36)
<PER-SHARE-DISTRIBUTIONS>                            0
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                               9.15
<EXPENSE-RATIO>                                    .84


</TABLE>