Abstract: 【Objective】The effects of high temperature stress on the growth and physiological response of juvenile mandarin fish(Siniperca chuatsi) were investigated from the aspects of antioxidant enzyme, digestive enzyme activities and heat shock protein family gene expression, which provided a reliable reference for the cultivation of juvenile S. chuatsi in practical production.【Method】Two-month-old juvenile S. chuatsi was subjected to acute high temperature stress for 96 h. The high initial lethal temperature(96 h-UILT₅₀) was measured by pre-test. The control group(26.0℃) and the acute high temperature stress group(36.0℃) were set by abrupt temperature rise method. Samples were taken at 0, 6, 12, 24, 48 and 96 h respectively after stress. Biochemistry kits were used to determine the activities of antioxidant and digestive enzymes, and real-time fluorescence quantitative PCR was used to detect the expression of heat shock protein family genes(HSP70αand HSP90α).【Result】The mortality rate of juvenile S. chuatsi increased with the increase of water temperature, and its 96 h-UILT₅₀ was 36.22℃. During the 96 h acute high temperature stress, the activities of superoxide dismutase(SOD) and catalase(CAT) in liver of S. chuatsi showed a decreasing, increasing and decreasing trend, while the activities of alanine aminotransferase(GPT) and the content of malondialdehyde(MDA) showed an increasing, decreasing and increasing trend. In terms of digestive enzymes, the activities of pepsin and intestinal amylase(AMS) of juvenile S. chuatsi showed a decreasing, increasing and decreasing trend, while the activities of intestinal lipase(LPS) showed an increasing, decreasing and increasing trend. In the process of acute heat stress, the relative expression of HSP70α gene in juvenile S. chuatsi showed a fluctuating trend of increasing to decreasing, and reached the highest value at 12 h of stress, and the second peak value appeared at 48 h of stress. The expression of HSP90α gene increased at first and then decreased, and reached the highest value at 24 h of stress. However, at 96 h of stress, HSP70α and HSP90α genes were still significantly higher than those of juvenile S. chuatsi in the control group(P<0.05).【Conclusion】The activity of antioxidant enzyme, digestive enzyme and the expression of heat shock protein gene of juvenile S. chuatsi are significantly affected by acute high temperature stress. Among them, heat shock protein genes HSP70α and HSP90α are involved in the physiological regulation of the response to high temperature stress to deal with the damage of liver cells under high temperature stress, so they can be used as markers of the response to high temperature stress.