Abstract: This study was conducted to investigate the effects of Resveratrol (RSV) supplementation on specific growth rate (SGR), nonspecific immunity function, antioxidant capability and disease resistance of blunt snout bream fed high-fat diet. This experiment was designed with five kinds of diets:a normal fat diet (NFD, 5% fat), a HFD (11% fat), and a HFD supplemented with 0.04%, 0.36%, and 1.08% RSV, respectively. At the end of 10-week feeding trial, fish were challenged by Aeromonas hydrophila at the concentration of 1×10⁷ CFU/mL, and the survival rate was recorded for the next 96h. The results showed that HFD supplemented with 1.08% RSV significantly reduced the SGR and average daily feed intake of blunt snout bream when compared to the other groups, the similar trend found in feed efficiency rate of blunt snout bream. In comparison with NFD, HFD significantly increased the levels of plasma MDA and NO, and decreased the level of plasma GSH in blunt snout bream. QRT-PCR results demonstrated that long-term HFD consumption induced the up-regulation of TNF-α, HSP70 and HSP90, which means HFD potently weaken antioxidant defenses in blunt snout bream. HFD supplemented with RSV at 0.04% significantly suppressed the activities of the plasma SOD. And yet, it not only significantly reduced the contents of plasma MDA and NO, but also significantly inhibited the activities of plasma SOD and CAT when HFD supplemented with 0.36% and 1.08% RSV. Besides, the plasma GSH content increased significantly when the fish fed HFD supplemented with 1.08% RSV. HFD supplemented with RSV at 0.04%, 0.36% and 1.08% all significantly increased plasma complement 3 content, enhanced lysozyme activities, and down-regulated the mRNA expressions of hepatic HSP70, HSP90 and TNF-α in blunt snout bream. After A. hydrophila challenge, the significant highest survival rate was observed in fish fed 1.08% RSV supplemented diet. In summary, when blunt snout bream was fed with high-fat diet for long time, the body was in a state of oxidative stress. And, the appropriate dose of RSV added could ameliorate the state of oxidative stress in the body, then the optimal dose of resveratrol was 1.08%.