Abstract:Allogynogemetic crucian carp ( average initial weight , 4. 2 .. 0. 3g ) were fed with basal diet supplemented 0. 1%, 0. 2%, 0. 4% Bacillus sp. , 0. 3%, 0. 6% , 1. 2% selenoyeast, complex of 0. 2% B . sp. and 0. 3%, 0. 6% , 1. 2% selenoyeast respectively for two months. Control group was fed with basal diet. Triplicate groups were made for each diet . The act ivit ies of protease and amylase in the intestine and hepatopancreas were determined. The activities of protease in the intestine and hepatopancreas fed with dietary 0. 2% B. sp. were 466. 2% and 85. 4% higher respectively than those of the control group. The activities of amylase in the intestine and hepatopancreas fed with dietary 0. 1% B . sp. were 83. 7% and 129. 5% higher respectively than those of the control group. The act ivit ies of protease in the intestine w ith three levels of selenoyeast were similar to those of the control group. The activity of protease in the hepatopancreas with dietary 0. 6% selenoyeast was 43. 7% higher than that of the control group, the act ivit ies of amylase in the intestine and hepatopancreas with dietary 0. 3% selenoyeast increased by 84. 2% and 163. 9% respectively. The activities of protease and amylase in the intestine fed with dietary 0. 2% B . sp. and 0. 3% selenoyeast complex were 395. 5% and 95. 4% higher respectively than those of the control group, while the activities of protease and amylase in the hepatopancreas fed with dietary 0. 2% B . sp. and three levels of selenoyeast were not remarkably higher than those of the control group. Compared to dietary 0. 2% B . sp. group, the activities of protease in the intestine and hepatopancreas fed w ith dietary 0. 2% B. sp. and three levels of selenoyeast complex decreased drastically w ith the increasement of the level of dietary selenoyeast, while there were no remarkable difference in the activities of amylase between two groups. Compared to dietary selenoyeast group, the activities of protease and amylase in the intestine and hepatopancreas fed with dietary selenoyeast and 0. 2% B . sp. complex were not changed remarkably.