OBJECTIVE： To observe the efficacy and safety of Bifid triple viable capsule in the treatment of ulcerative colitis （UC）. METHODS： 94 patients with UC were randomly divided into control group and research group. Control groups was given nutrition support， light diet and 5-amino salicylic acid and other conventional treatment； research group was additionally given 420 mg Bifid triple viable capsule， 3 times aday. Treatment course for both group was 8 weeks. The clinical efficacy， and serum D-lactic acid， diamine oxidase （DAO） levels before and after treatment， and incidence of adverse reactions in 2 groups were observed. RESULTS：The total effective rate in research group was significantly higher than control group， the difference was statistically significant（P＜0.05）； after treatment， serum D-lactic acid， DAO levels in 2 groups were significantly lower than before， and research group was lower than control group， the differences were statistically significant（P＜0.05 or P＜0.01）； and there was no significant difference in the incidence of adverse reactions（P＞0.05）. CONCLUSIONS： Based on the conventional treatment， both the efficacy and safety of Bifid triple viable capsule are good in the treatment of UC.