Abstract: OBJECTIVE To explore the protective effect and mechanisms of daucosterol on acute liver injury induced by concanavalin A(conA). METHODS Fifty C57 BL/6 mice were randomly divided into 5 groups:normal group, model group, low, medium and high dose group of daucosterol, 10 rats in each group. After injection of conA into the tail vein, the daucosterol was administered immediately in each group of daucosterol. After 12 h, killed the animals. The liver index was measured, and the activity of alanine aminotransferase(ALT), aspartate aminotransferase(AST) and the contents of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β) and interleukin-6(IL-6) in serum were detected. The pathological changes of liver tissue were observed by HE. qRT-PCR was used to detect the transcription levels of TNF-α, IL-1β and IL-6 in liver. Western blotting was used to detect the expression of STAT3 and p-STAT3. RESULTS The indexes of each group of daucosterol were lower than the model group(P<0.05 or P<0.01), such as the content of ALT, AST, TNF-α, IL-1β, IL-6 in serum, the expression of TNF-α, IL-1β, IL-6 mRNA in liver, and the levels of STAT3 and p-STAT3 in liver. The results of HE staining also showed that the treatment of daucosterol can effectively reduce liver damage. CONCLUSION Daucosterol has a protective effect on liver injury induced by conA, which may be related to inhibition of STAT3 expression and activation.