To investigate the effect of high temperature stress on growth performance and activities of antioxidant enzymes in juvenile olive flounder Paralichthys olivaceus,the survival,growth,feeding,activities of superoxide dismutase (SOD) and catalase(CAT) of olive flounder at different temperatures (25 ℃,28 ℃,30 ℃,31 ℃ and 32 ℃)were compared.The results showed that the survival rate of juvenile olive flounder was 100%at the temperatures of 25 ℃,28 ℃,and 30 ℃,and the survival rate was 95%±1.18% at the temperature of 31 ℃.Nevertheless,the survival rate was (20.83%±2.20%) at the temperature of 32 ℃.The water temperature significantly affected the specific growth rate(SGR),feeding rate(FR) as well as feed conversion efficiency(FCE) of juveniles.A quadratic regression was fit to describe the relationship between the SGR,FR,FCE and the water temperature(SGR:R²=0.93;FR:R²=0.90;FCE:R²=0.86;P<0.01).The SGR,FR and FCE reduced with increasing water temperature in the temperature range of 25-32 ℃. Moreover,SOD and CAT activities in liver were measured under high temperature stress and the two critical antioxidant enzymes were also significantly affected by high water temperature.The activities of SOD and CAT declined with the increasing water temperature.This study indicated that the temperature of 32 ℃ may be the upper limit for olive flounder,and the high water temperature has a significant effect on growth performance and activities of antioxidant enzymes of olive flounder.Our results would be good references for genetic breeding and healthy culture of olive flounder.