Abstract: To assess the effects of dietary supplementation with glutathione (GSH) on tissue GSH levels, immunity, and antioxidant capacity of juvenile yellow catfish (Pelteobagrus fulvidraco), a total of 800 yellow catfish with a mean body weight of (1.32±0.01) g were considered and randomly divided into 5 groups with 4 replicates per each group and 40 fish per each replicate as well. During 56d, the fish were fed by a basal diet and four test diets, which supplemented with 100, 300, 500, and 700 mg/kg of reduced GSH, respectively. The results indicated that, except for 100 mg/kg group, supplementation with GSH significantly increased the GSH content in liver and serum of yellow catfish (P<0.05). When GSH level was 300 mg/kg or higher, GSH content in liver and serum was in a stable state. With the increase of glutathione level, the immunity and antioxidant indices were initially increased, and then decreased. The lysozyme and alkaline phosphatase activities in 300 and 500 mg/kg groups, immunoglobulin M (IgM) and complement component 4 (C4) contents in 300 mg/kg group, and acid phosphatase activity in 500 mg/kg group markedly increased, compared with the control group (P<0.05). There were no significant differences (P>0.05) in complement component 3 (C3) and nitric oxide contents among all groups. Compared with the control and 700 mg/kg groups, the liver superoxide dismutase, catalase and glutathione peroxidase activities, total antioxidant capacity and the serum superoxide dismutase, as well as glutathione peroxidase activities in 300 mg/kg group were significantly higher (P<0.05), while the serum malondialdehyde content in that group was considerably lower (P<0.05). Under ammonia-nitrogen stress for 96h, compared with the control group, the liver and serum superoxide dismutase, catalase, and glutathione peroxidase activities in 300 mg/kg group were significantly greater (P<0.05), however, the serum malondialdehyde content in the mentioned group was significantly lower (P<0.05). In conclusion, dietary supplementation with GSH could enhance the tissue GSH level, immunity and antioxidant capacity of juvenile yellow catfish, and the effective range of this enhancement was 300 to 500 mg/kg as well.