Abstract: OBJECTIVE To investigate the effect of capsaicin on acute liver injury rats induced by carbon tetrachloride. METHODS Thirty SD rats were randomly divided into five groups:control group, model group, capsaicin low dose, medium dose and high dose group, six rats in each group.In addition to the normal control group, the other four groups were intraperitoneally injected with 5 ml·kg^-1 25% carbon tetrachloride solution for acute liver injury. In the capsaicin low, medium and high dose group were given intraperitoneal injection of capsaicin of 1.0, 2.0, 5.0 mg·kg^-1, blank group and model group were injected with same volume peanut oil for 5 d. After 1 d of the last administration, the liver and serum were taken from the rats, and the serum alanine aminotransferase(ALT), aspartate aminotransferase(AST), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) were measured. RESULTS The levels of ALT and AST in the serum of the experimental groups were significantly lower than those in the model group(P<0.05), while the activity of CAT was significantly higher than that of the model group(P<0.05). The SOD activity in the middle and high dose capsaicin group were significantly higher than those in the model group(P<0.05), while the MDA content were significantly lower than model group(P<0.05). Compared with the model group, the SOD activity of low dose experiment group also increased, and MDA content decreased, but there was no significant difference. CONCLUSION Capsaicin has a protective effect on SD rats with acute liver injury caused by carbon tetrachloride. The mechanism may be related to oxidative stress.