Changes of fr eshness index , free amino acids and taurine dur ing stor age and f resh preservation of Ost rea Pl icatula in low tempera tur e were studied in this exper iment .The experimental resul ts show that when stored in 0 ～ 2 ℃ and 3 ～ 5 ℃, VBN incre ased gentlely with 15 .2mg/100g and 20 .6mg/100g r espect ively af ter 15days stor age . The ir f reshness almost maintained in be tter quality .However , when stored in 6 ～ 8 ℃, VBN ch anged faster than the above , and the quality of oyster enter ed an init ial decomposition stage after 15 days stor age .In oyster ext racts solution the maximum content of taurine was reduced slight ly and kept the fluctuation in the r ange of 357mg/100g ～ 387mg/100g during stor age .The amounts of f ree amino acids in Ala , Gly , and Glu wer e higher than those of Ser , Arg , Lys , wher eas the init ial amounts of other amino acids were rela tivly low .Changes of amount in fr ee amins acids were different whe n stor ed in var ious temper atur es , but they showed the ir own change pat term.