In this study, we tested the high temperature mutation tolerance，survival and immune enzyme activity under different high temperature level of Mizuhopecten yessoensis. There are two stages in our laboratory experiments, firstly, we transferred scallops from the rearing temperature (15℃,control temperature) to 20、22、24and 26℃, and then we tested the survival and related immune indicators of M.yessoensis. The survival of M.yessoensis was not affected by temperature from 15℃ to 22℃ with survival rate exceeding 85.21%, and there is no significant difference in different group (P＞0.05), Scallops exposed to 26℃ were significantly affected by temperature, with a survival of 26.33%. With the temperature rising, the T-AOC and MDA content In the body cavity fluid of M.yessoensis significantly changed (P＜0.05). The CAT vitality would rise after the first drop with the rise of temperature. There were no significant differences among different groups SOD vitality (P＞0.05). Secondly, we abruptly transferred scallops from the rearing temperature (15℃,control temperature) to 20、22、24 and 26℃ level, and examined related immune index in the presence of 1h, 2h, 4h, 8h, 12h, 24h, 48h and 96 h. The results showed that, The survival of M.yessoensis was not affected by temperature from 15℃ to 24℃ during the 96-h exposure periods with survival rate exceeding 82.29%. Scallops exposed to 26℃ were significantly affected by temperature, with a survival of 0% after 12h. The 8-, 12-, 24-, 48- and 96h lethal temperature for 50% (LT50) were 27.52, 24.41, 24.37, 24.24 and 23.81℃ respectively.