Abstract: An experiment was conducted to study the effects of coated vitamin C with different supplementation levels(0, 500, 1 000, 2 000 and 4 000 mg·kg^-1diet)on growth and non-specific immune response of largemouth bass(initial weight about 19 g) for 1 month.Each treatment was stocked with 50 basses and was run in triplicate.The results showed that in one month feeding trial, the diets with coated vitamin C supplementation could significantly increase the growth rate and spleen weight: body weight of largemouth bass(P < 0.05).While the survival rate, hepatopancreas weight: body weight were not affected(P>0.05).The superoxide dismutase(SOD) and lysozyme activity of serum increased significantly for the dietary with vitamin C supplementation(P < 0.05).The ascorbic acid concentrations in the largemouth bass hepatopanereas increased significantly with the increase of the diet vitamin C supplementation levels(P < 0.05).The results indicated that Vc played an important role in antioxidation, promoting growth and non-special immunity of largemouth bass.