This experiment was to conducted to investigate the effects of Bacillus subtilis on growth performance, antioxidant function and intestinal morphology of broilers. A total of 420 one-day-old male Arbor Acres (AA) broilers were selected and randomly divided into 4 groups with 7 replicates per group and 15 broilers per replicate. Broilers in the control group were fed a basal diet, broilers in the Bacillus subtilis group were fed the basal diet supplemented with 200 g/t Bacillus subtilis, broilers in the bacitracin zinc group were fed the basal diet supplemented with 250 g/t bacitracin zinc, and broilers in the Bacillus subtilis + bacitracin zinc group were fed the basal diet supplemented with 200 g/t Bacillus subtilis+250 g/t bacitracin zinc. The experiment lasted for 42 days. The results showed that compared with the control group, dietary Bacillus subtilis significantly increased the average daily gain (ADG) during 22 to 42 days of age and serum malondialdehyde (MDA) content of broilers (P<0.05), while significantly decreased the ADG, average daily feed intake (ADFI) during 1 to 21 days of age and serum superoxide dismutase (SOD) activities and crypt depth of jejunum of broilers (P<0.05). Dietary Bacillus subtilis and bacitracin zinc had significant interactions on the feed to gain ratio during 22 to 42 days of age, European benefit index during 1 to 42 days of age and liver MDA content of broilers (P<0.05). In summary, diet supplemented with 200 g/t Bacillus subtilis can improve the growth performance of broilers during 22 to 42 days of age, improve the morphology of jejunal mucosa to a certain extent; and diet supplemented with 200 g/t Bacillus subtilis and 250 g/t bacitracin zinc can improve the growth performance of broilers.