Abstract: To evaluate the effects of dietary protein levels on the growth, digestive enzymes activities, non-specific immunity, as well as protein metabolism of Schizothorax o’connori, 6 equal fat and equal energy diets were formulated containing 20.01%, 25.00%, 30.19%, 35.24%, 40.12% and 45.10%, respectively, for a 94-day trial. A total of 540 Schizothorax o’connori with the average initial weight of (115.46±16.20) g were randomly distributed into six groups with three replicates per group, containing 30 Schizothorax o’connori per replicate. The results indicated that with the increase of dietary protein level, the final weight (FW), weight gain rate (WGR), specific growth rate (SGR) increased first and then decreased with the maximum level at 40.12% group that was not significantly different from that of 30.19% group (P>0.05). The protein efficiency ratio (PER) and survival rate (SR) increased first and then decreased with the maximum level in 25.00% group that was not significantly different from that of 30.19% group (P>0.05). The feeding ratio (FR) decreased first and then stabilized with the highest level in 20.01% group that was significantly higher than other groups (P<0.05). The feed conversion ratio (FCR) and hepaticsomatic index (HSI) decreased first and then increased with the lowest level in 40.12% group that were not significantly different from those of 35.24% group (P>0.05). Whole fish crude protein content increased significantly (P<0.05). The activity trends of trypsin (TPS), lipase (LPS) and amylase (AMS) were basically consistent with SGR, WGR and PER, and TPS > LPS > AMS. The activity of superoxide dismutase (SOD) in hepatopancreas increased with the maximum level in 45.10% group that was not significantly different from 30.19%—40.12% groups (P>0.05). Alanine transaminase (ALT), acid phosphatase (ACP) and alkaline phosphatase (AKP) increased first and then decreased with the highest ALT and ACP level in 35.24% group and the highest AKP in 30.19% group, and there were not significantly different among groups (P>0.05). Urea nitrogen increased significantly (P<0.05). The highest serum ammonia was in 45.10% group, which was significantly higher than 25.00% group (P<0.05). Based on the quadratic regression analysis of the WGR, SGR, FCR, PER and dietary protein levels, the optimal dietary protein level of Schizothorax o’connori was 31.20%—34.02% under the experimental condition.