The experiment was conducted to study the effects of Bacillus subtilis on growth performance, activities of intestinal digestive enzyme and blood biochemical indices of Pelodiscus sinensis. Thirty juvenile Pelodiscus sinensis with an average initial body weight of (11.96±0.49) g were randomly divided into 5 groups, which were fed diets containing 0 (control group), 0.5 (group Ⅰ), 1.0 (group Ⅱ), 2.0 (group Ⅲ) and 5.0 g/kg (group Ⅳ) Bacillus subtilis, respectively. There were 2 replicates per group and each replicate contained 3 animals. The feeding trial lasted for 30 days. Growth performance, activities of intestinal digestive enzyme and blood biochemical indices were determined at the end of the experiment. The results showed as follows: the weight gain rate and special gain rate in groups Ⅱ and Ⅲ were significantly higher than those in control group and groups Ⅰ, Ⅳ (P＜0.01), and the feed conversion rate in groups Ⅱ and Ⅲwas significantly lower than that in control group and groups Ⅰ, Ⅳ (P＜0.01). Activities of intestinal digestive enzyme in experimental groups were significantly higher than those in control group (P＜0.05). Among them, group Ⅰ showed the highest activities of protease and amylase, and the activities of amylase in groups Ⅰ, Ⅱ and Ⅲ were significantly higher than those in control group and group Ⅳ (P＜0.05). Activities of aspartate aminotransferase, alanine aminotransferase, creatine kinase and concentration of creatinine in experimental groups were significantly lower than those in control group (P＜0.01). Activities of lactate dehydrogenase in the experimental groups were significantly lower than those in control group (P＜0.05), except group Ⅲ. Concentrations of protein, glucose and lipid were no significant differences among all groups (P＞0.05), except the concentrations of total protein and globulin in group Ⅳ were significantly lower than those in control group (P＜0.05). These results indicated that proper level of Bacillus subtilis supplementation in the diet could increase growth performance and activities of intestinal protease and amylase, and decrease feed conversion rate. Furthermore, it could protect the liver, heart, kidney and muscle, and decrease the level of anaerobic metabolism. The recommended optimum levels of Bacillus subtilis was from 1.0 to 2.0 g/kg in the diet of juvenile Pelodiscus sinensis.［Chinese Journal of Animal Nutrition, 2010，22（1）:235-240］