Abstract: The paper aims to study the effect of Bacillus subtilis on performance, egg quality and blood biochemical parameters of Rugao yellow chicken. The authors chose 250 47-week-old Rugao yellow chicken with good body condition and similar production performance, and divided them into 5 groups randomly with 5 repetitions per group and 10 per repetition. The control group Ⅰwas fed with the basal diet and Bacillus subtilis was added with the certain ratio of 0.02%, 0.075%, 0.2%, 0.75% into the basal diet for group Ⅱ-Ⅴ; the experiment lasted 42 days. The results showed that: (1) there was no significant difference between laying rate, average egg weight, average daily egg weight, average daily feed intake and ratio of feed to egg (P＞0.05) in each groups; (2) on the 42nd day, the albumen height of group Ⅴ was extremely and significantly higher than that of the control group (P<0.01) and was significantly higher than that of group Ⅱ (P<0.05); and the albumen height of group Ⅲ and Ⅳ was significantly higher than that of the control group (P<0.05); HA units of group Ⅴ was extremely and significantly higher than that of the control group (P<0.01) and was significantly higher than that of group Ⅱ (P<0.05); (3) on the 42nd day, the content of the urea nitrogen of group Ⅳ was extremely and significantly lower than that of the control group (P<0.01) and was significantly lower than that of group Ⅱ (P<0.05); the content of uric acid of group Ⅳ was extremely and significantly lower than that of the control group (P<0.01) and that of group Ⅱ was significantly lower than that of the control group (P<0.05). The basal diet added with Bacillus subtilis can improve the production performance, egg quality, blood biochemical parameters of Rugao yellow chicken, raise the feed digestion rate and reduce the emissions of nitrogen and phosphorus in faeces.