Abstract： Objective To observe the effect of Kuiyu dection on ulcerative colitis and to explore its mechanism.Methods 120 patients with ulcerative colitis were randomly divided into a treatment group and a control group,60 cases in each group.The treatment group was treated with Kuiyu dection retention enema,1 time a day,15 days for a course of treatment; and the control group was treated with SASP orally,2 g every time,3 times a day,and 15 days for a course of treatment.All patients with a course of treatment for the next 7 days after the rest period of treatment,evaluated after 3 courses.Comprehensive clinical efficacy,the main symptoms,score of integral electronic colonoscopy examination,and the changes of IL-6,IL 8 levels were observed in both groups after treatment with complete remission and six months followed-up,besides,the recurrence rate was also observed.Results The total effective rate was 93.33％ in the treatment group,better than the control group 78.33％ (x2 =9.027,P＜0.05) ; the treatment group also showed better results in diarrhea,pus and blood improvement than the control group (x2=5.630、x2=5.972,P＜0.05),the treatment group could significantly reduce UC Serum IL-6,IL-8 level (x2=8.314,P＜0.01); electronic colonoscopy examination points,hyperemia,erosions,ulcers in both groups were significantly improved,but the treatment group was significantly better than the control group (x2=8.322,P＜0.05) ; 6 months followed-up and the recurrence rate in treatment group were better than control group,and the difference was statistically significant (x2=5.857,P＜0.05).Conclusion Through decreasing the IL-6,IL 8 levels,Kuiyu dection can treat ulcerative colitis,with significant effect,non-toxic side effects,inexpensive,and easy for use.