The effects of low salinity on the growth performance, serum biochemical indices, and non-specific immunity of Maccullochella peelii peelii were evaluated. After acclimating to different salinities, Maccullochella peelii peelii was cultured in four experimental groups for 60 days with salinities of 0, 3, 6, and 9, respectively. The results showed that:the final body weight was significantly decreased with the increasing salinity (P<0.05); Additionally, the feed conversion ratio attained an optimum value when the salinity was 0 (1.11±0.11); and the survival rate was the highest when the salinity was 3 (98.33%±2.89%). The serum indices showed that:Creatinine levels followed a decreasing trend with the increasing salinity; Urea nitrogen content increased with the increasing salinity levels, i.e. in the salinity 9[(7.00±0.26) mmol/L], which was significantly higher than that of group 0 (P<0.05). Notably, there were no significant differences in other indicators evaluated. The activities of non-specific immune enzymes were significantly affected by the salinity. The activities of alkaline phosphatase and lysozyme were the highest when the salinity was 3. Also, the activity of superoxide dismutase was the highest when the salinity was 6, which was significantly higher than that in other groups. The catalase activities of groups 0 and 6 were significantly higher than that in other groups. In summary, the water salinity level of 3 was found to be suitable for the cultivation of Maccullochella peelii peelii.