Abstract: Effects of Bacillus subtilis J-11 preparation on five kinds of digestive enzyme activity in intestinal tract and growth performance of broiler were studied. 2000 three-day-old broilers were divided into test group (supplemented with 0.1% J-11 preparation from 3 days old to 21 days old) and control group (fed by the basal diet) on the average. The results showed that 琢-amylase, protease, lipease, cellulase activity in broiler manure increased by 44.02%, 45.99%, 58.37%, 45.73%, respectively, while 茁-gluanase activity was not different. Broiler weight increased by 13.0%, feed to gain ratio decreased by 11%. When J-11 preparation was stopped feeding those indices of test group were close to those of control group gradually. J-11 preparation can improve some intestinal digestive enzyme activity in intestinal tract and growth performance of broiler.