Objective :To observe the effect of Shenling Baizhu Powder which can strengthen spleen and resolve damp in the treatment of 72 cases of ulcerative colitis. Methods :The traditional formula of Shenling Baizhu Powder was used and modified according to the syndromes. The effect was compared with single Western medicine. Results :The total effective rate of treatment group was 95.3% and that of control group was 78.4%(P0.05). Conclusion :This formula can strengthen spleen and supplement Qi as well as resolve damp and stop diarrhea so as to achieve good effect on treating ulcerative colitis.