Abstract: The aim of this research was to evaluate the effects of Bacillus licheniformis on blood physiological and biochemical indices in cultured sea bass (Lates calarifer). Seven levels of B.licheniformis powder product were supplemented to a basal diet at 0，1.0, 2.0，3.0，4.0，5.0 and 6.0 gkg-1 diet respectively. The results showed that the blood physiological indices such as RBC, WBC, HCT and Hb were not affected. Among the blood biochemical indices, GLU and BUN were lower in the experimental group than the control. Serum TP was promoted in the experimental group. In the treatment with dietary B.licheniformis powder at 2.0 gkg-1 diet, sea bass got the lowest GLU and BUN. Serum TP was highest when B.licheniformis powder was added at 4.0 gkg-1 diet and was siginficantly higher than the control group. The serum CHO of sea bass was significantly lower than the control group when B.licheniformis powder was added at 3.0 gkg-1 diet. The sea bass serum ALT and LDH were also reduced by B.licheniformis. Except the group of B.licheniformis added at 2.0 and 3.0 gkg-1 diet, the ALT of the rest groups were all significantly lower than the control group (P0.05). As to the serum LDH, only the group B.licheniformis added at 1.0 gkg-1 diet was significantly lower than the control group (P0.05).