Abstract： Objective： To observe the clinical effect of the therapy of modified Longdan Xiegan tang combined with magnesium isoglycyrrhizinate on drug- induced hepatitis. Methods：A total of 68 patients with drug- induced hepatitis were randomly divided into the control group and the treatment group，with 34 cases in each group. The control group was treated with magnesium isoglycyrrhizinate， and the treatment group was additionally treated with modified Longdan Xiegan tang based on the treatment of the control group. Both groups were continuously treated for four weeks. The clinical effects， changes of liver function indexes， including alanine aminotransferase(ALT)， aspartate aminotransferase(AST)， alkaline phosphatase(ALP)， and total bilirubin(TBil)， and adverse reactions were observed and compared between the two groups. Results：The total clinical effective rate was 97.06% in the treatment group and 82.35% in the control group，the difference being significant(P＜0.05). Before treatment，there was no significant difference being found in the comparison of levels of ALT，AST，ALP and TBil between the two groups(P＜0.05). After treatment，the levels of ALT，AST，ALP and TBil in the two groups were decreased when compared with those before treatment(P＜0.05)，and the above indexes in the treatment group were lower than those in the control group(P＜0.05). The incidence of adverse reactions was 5.88% in the treatment group and 14.71% in the control group， the difference being significant(P＜0.05). Conclusion： The therapy of Longdan Xiegan tang combined with magnesium isoglycyrrhizinate has a definite curative effect on drug-induced hepatitis，which can effectively relieve the clinical symptoms of patients， improve the liver function， and reduce the incidence of adverse reactions.