Abstract: The study was conducted to explore the effects of dietary protein levels on growth,digestive enzymes activities and antioxidant ability of hybrid yellow catfish (Pelteobagrus fulvidraco♀×P.vachelli♂).Five experimental diets were formulated containing dietary protein 30%,35%,40%,45% and 50%,respectively.Hybrid yellow catfish (1.00±0.05)g were fed with five experimental diets for 60 days.The objective of this experiment was to determine the dietary protein requirement of hybrid yellow catfish.The results indicated that the dietary protein level was 40%-45%,the growth performance of hybrid yellow catfish was the best,and the final weight,specific growth rate (SGR) were increased significantly (P<0.05).The activity of protease in stomach and intestine in 40% protein group was the highest,the activity of lipase and amylase in 45% protein group was the highest.In all groups,the activity of protease in stomach was higher than that of intestine.The activities of lipase and amylase in intestine were higher than that of stomach when the dietary protein level exceeded 40% (including 40%).The activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) in the liver of hybrid yellow catfish were significantly higher than that of other groups (P<0.05) when the dietary protein level was 40%-45%.The catalase (CAT) activities were higher than those of other groups when the dietary protein level exceeded 40% (including 40%).The content of malonaldehyde (MDA) decreased and then increased with the increase of dietary protein level.In conclusion,the optimal dietary protein level of hybrid yellow catfish (1.00±0.05)g was 40%-45%.