A breed trial was conducted on juvenile fish with initial body weight of(22.40±0.30 ) g for 8 weeks at controlled temperature in single recirculating system Fish meal and dehulled soybean meal were used as protein source. Five isonitrogenous (40% protein) and isoenergetic (15.8MJ/kg ) diets

with dehulled soybean meal replacing level 0%（CK）

15%

30%

45% and 60% of fish meal protein

were formulated to feed juveniles in order to investigate the effects of dietary dehulled soyabean meal replacing fish meal on the activity of digestive enzyme and intestinal tissue of Clarias lazera . The results indicated that pepsin activity of Clarias lazera in dehulled soyabean meal groups was significantly lower than that in control group （P＜0.05）.The activity of protease in the midintestine and the Hepatopancrea decreased significantly for 30%

45% and 60% replacing level（P＜0.05）

the activity of protease in the anterior intestine and posterior intestine decreased significantly for 45% and 60% replacing level（P＜0.05）

and the activity of amylase in the posterior intestine was significantly lower than that in control group for 45% and 60% replacing level（P＜0.05）.But there were no significant difference in the activity of amylase in the stomach，anterior intestine and midintestine of Clarias lazera in each group （P＞0.05）. The dehulled soyabean meal had no significant effects on lipase of Clarias lazera(P＞0.05). Dehulled soyabean meal replacing fish meal had some effects on morphology of intestinal tissue of Clarias lazera. Meanwhile

the structural integrity of anterior intestine and midintestine in 45% and 60% group was destroyed

the part of intestinal villi shed

the part of epithelial cells and proper layer separated

the connective tissue of proper layer loosened

and the proper layer became wider. The length of intestine

index of intestine body

index of the length of intestine and the enteroplica height of intestine decreased significantly（P＜0.05）.