The present study aimed to determine the effects of dietary nano-selenium (0.0 mg/kg, 0.2 mg/kg, 0.4 mg/kg, 0.8 mg/kg) added to feed for eight weeks on growth, muscle composition, serum biochemical and antioxidant indices of individuals with similar body weight (98.75±5.74 g) were randomly assigned to four groups with three replicates per group and 30 fish per replicate. Fish were starved for 24 h before sampling, and body weight, length, and width were prepared for measurement of growth indicators. The head, kidneys, spleen, liver, mesonephros, and intestines were prepared for the immune organ index. Muscle was prepared for body composition analysis. Blood samples were collected from the caudal vein and were used directly to assay indicators in the serum of . The results were as follows. Compared with the control group (basal diet), specific growth rate (SGR) and intestinal weight index (IWI) were increased, and feed conversion ratio (FCR) was decreased, with the increasing of supplement of nano-selenium (<0.05). Weight gain rate (WGR) also increased when diets were supplemented with 0.2 mg/kg nano-selenium. The intestinal ratio (IR) of was significantly increased when 0.4 mg/kg and 0.8 mg/kg nano-selenium was added (<0.05). Additionally, the crude protein content of muscles was significantly increased when 0.4 mg/kg and 0.8 mg/kg nano-selenium was added (<0.05). Compared with the control group, the serum globulin (GLOB), triglyceride (TG), and cholesterol (TC) content of the fish were significantly increased when diets were supplemented with different doses of nano-selenium (<0.05). At the same time, the serum superoxide dismutase (SOD) activity of fish was significantly increased, and the serum malondialdehyde (MDA) and glucose (Glu) content of fish were significantly decreased (<0.05) in the Se supplemental group. The serum glutathione peroxidase (GSH-Px) activity of was significantly increased when 0.4 mg/kg and 0.8 mg/kg nano-selenium was added to the diet. Serum nitric oxide synthase (iNOS) activity and muscle selenium content was significantly increased when 0.8 mg/kg nano-selenium was added. Taken together, the results showed that nano-selenium had certain effects on the growth and development of the fish, and that it improved muscle quality and serum antioxidant performance. The optimal levels of dietary nano-selenium supplement in were estimated to be 0.52 mg/kg using quadratic regression analysis based on specific growth rate. Through comprehensive consideration of growth performance, antioxidant status, and lipid metabolism, the supplement level of 0.5 mg/kg nano-selenium is recommended in diets of . This study provides a new theoretical basis for the development of nutritional feed for .