This experiment was designed to investigate the effects of  Bacillus licheniformis  on the activities of digestive enzymes, immunological and antioxidant indices of freshwater pearl mussel Hyriopsis cumingii . One hundred and forty four 2-year-old freshwater pearl mussels were randomly assigned to 4 treatments with 3 replicates of 12 freshwater pearl mussels.  Bacillus licheniformis were added to the aquaculture water of 4 treatments with the final concentration of 0 (control), 0.5×10⁶,1.0×10⁶, and 2.0×10⁶ cfu/mL, respectively. The experiment lasted for 30 days. The results showed that compared with the control group, the weight gain rate of the mussels in test groups increased significantly （P<0.05）,and the 1.0×10⁶ cfu/mL group had the highest weight gain rate which was significantly higher than that of 0.5×10⁶ and  2.0×10⁶ cfu/mL groups . The activities of amylase, lipase and protease of mussels in the 1.0×10 6 cfu/mL group showed a significant increase (P<0.05) on the 15 ^th  day, and the activities of lipase and protease returned to the level of control group (P>0.05) on the 30^th day. The activities of lysozyme of mussels in all the test groups and the activities of phenoloxidase in the 0.5×10⁶ and 1.0×10⁶ cfu/mL groups increased significantly （P<0.05） in the experiment, respectively. Along with increasing the level of Bacillus licheniformis , the activities of acid phosphatase and alkaline phosphatase increased, and those in the 1.0×10⁶, 2.0×10⁶ cfu/mL groups increased significantly (P<0.05) on day 15 and returned to the level of control group (P>0.05) on day 30. The total antioxidant capacity and the activities in superoxide dismutase in test  groups increased significantly on day 15 except the 0.5×10⁶ cfu/mL group ,and no significant difference (P>0.05) was observed between the 1.0×10⁶ and 2.0×10⁶cfu/mL group. The activity of catalase in 1.0×10⁶ cfu/mL group increased significantly on day 15 (P<0.05), and returned to the same level of control group on day 30 (P>0.05). There was no significant difference in the concentration of maleic dialdehyde among the groups. It was concluded that the  Bacillus licheniformis  added to water could increase the activities of digestive enzymes, immunological and antioxidant indices and promote the growth of  Hyriopsis cumingii . The optimum addition level was 1.0×10⁶ cfu/mL and the addition interval of  Bacillus licheniformis was 15 days.