Objective:To study the protective effects of steamed Codonopsis lanceolata(SCL)on alcohol-induced acute liver injury in mice. MethodsMale ICR mice were randomly divided into the blank control group, model group, silymarin group, SCL groups with low-, medium-and high-dose. Except the blank control group, mice model of acute liver injury was established by alcohol in the other groups. Each group was received the corresponding intervention. The serum levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),triglyceride(TG)and the liver contents of reduced glutathione(GSH)and malondialdehyde(MDA)were determined by colorimetry. The pathological changes of liver tissue were observed and the histopathological scores were evaluated.  Results:Compared with the blank control group,the serum levels of ALT,AST and TG were increased in the model group,and the content of MDA was increased and the activity of GSH was decreased in liver,with statistically significant differences(P<0.05). Compared with the model group,the serum levels of ALT,AST and TG were significantly decreased in mice treated with SCL,and the content of MDA was decreased and the activity of GSH was increased in liver,with statistically significant differences(P<0.05). The results of HE staining showed that the obvious liver injury was observed in the model group,which performed as the cells necrosis, fatty degeneration of adjacent hepatocytes and infiltration of lymphocytes. But no severe steatosis was observed in the SCL group with high-dose,and the liver injury and the fragmentation degree of liver structure was the slightest.  Conclusion: Steamed Codonopsis lanceolata shows protective effects on alcohol-induced acute liver injury in mice. Its mechanism may be related to the improvement on lipid peroxidation.