Abstract: Objective To evaluate the effect and adverse events of S-adenosyl methionine on acute cholestasis hepatitis patients. Methods Total of 76 patients with acute cholestasis hepatitis were randomly divided  into two groups: the control group (29 cases) were intravenously injected with diammonium glycyrrhizinate and Yinzhihuang, while the S-adenosyl methionine therapeutic group (47 cases) were treated with S-adenosyl methionine (1000 mg/d) besides the above medicines. After treatment for 2, 4 and 6 weeks, the manifestations changes were estimated and the clinical symptoms, serum parameters of liver function (TBil, ALT, AST, ALP, GGT) and adverse events were detected for both groups. Results After treatment for 2, 4 and 6 weeks, descents of serum TBil in the therapeutic group were 46%, 77%, 92%, respectively, which were 37%, 60% and 90% in the control group. Clinical symptoms were improved in both groups. The improvement rate of skin pruritus in therapeutic group (70.0%) was significantly higher than that in control group (45.0%). Conclusions S-adenosyl methionine can decrease jaundice rapidly, especially in 4 weeks, also it may improve skin pruritus significantly and no serious adverse events were reported.