To investigate the protective effect of Dehydrocostus lactone on liver injury in experimental rats. Methods: Rats were injected with galactosamine and carbon tetrachloride to induce liver injury. The model rats were randomly divided into normal group, vehicle control, positive control group (0.2 mg·kg-1), high, middle, and low Dehydrocostus lactone dose groups (45, 15 and 5 mg·kg). The changes of activity of ALT, AST in serum and MDA content in liver tissue were measured. The pathologic change of liver tissue was examined under light microscope by HE and Masson staining. Results: Compared with the vehicle group, Dehydrocostus lactone remarkably decreased (P< 0.05) the activities of ALT, AST in serum and MDA content in liver tissue. It was observed that Dehydrocostus lactone could significantly alleviate the necrotic pathologic change of liver tissue. Conclusion: Dehydrocostus lactone has protective effects on liver injury in labortary rats.