The aim of this research was to evaluate the effects of Bacillus coagulans on growth performance,digestive enzymes and some serum nonspecific immune enzymes in cultured sea bass (Lates calarifer). Four levels of B.coagulans powder product was supplemented to a basal diet at 0 (the control group), 0.1 % (group 1), 0.5% (group 2) and 1.0% (group 3) g/kg feed,respectively.Diets were fed to sea bass with initial body weight of (18.95 ± 0.27) g for 50 days.The sea bass was randomly distributed into 4 groups,each group with 3 replicates in circular fiberglass reinforced plastic tanks with volume of 0.5 m³.The results showed that the weight gain and the specific growth rate were highest in group 2,and were 9.54% and 4.01% higher than that of the control,respectively,but there was no significant difference among the groups (P>0.05). There was no significant difference in the digestive enzymes of the intestinal and pyloric caeca within groups.But the liver protease of the group 2 was significantly lower than that of the control,while the amylase of stomach of the group 3 was significantly higher that of the control (P<0.05). There was no significant difference in some serum immune enzymes (AKP,POD,SOD) among groups (P>0.05). This research indicated that the B.coaglucans could improve the growth of the sea bass slightly.It affected the liver protease and the stomach amylase,too.The serum was slightly affected.