Objective To investigate the changes of Th1/Th2 cytokines and its relationship with lipopolysaccharide (LPS) in pretreatment of relieving nonalcoholic steatohepatitis (NASH).Methods The 24 male Wistar rats were randomly divided into 3 groups: normal control group, liver injury group and LPS pretreatment group. The rats were given normal diet in normal control group,high-sucrose and high-fat diet both in liver injury group and in LPS pretreatment group, and the rats in LPS pretreatment group were given hypodermic injection of LPS 0. 5 mg/kg every other day. The level of plasma endotoxin (ET), activity of alanine aminotransferase (ALT), content of tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were determined. At the end of week 9, the rats were executed, and the liver tissue slices were prepared to investigate hepatic pathologic change by hematoxylin and eosin (HE) staining.Results The level of plasma ET was significantly higher in liver injury group than in normal control group. The level of plasma ALT and infiltrating lymphocytes in liver tissue were significantly lower in LPS pretreatment group than in liver injury group. The level of plasma TNF-α was significantly lower in LPS pretreatment group compared with liver injury group.In contrast, the level of plasma IL-10 was higher (P＜0. 05). Histology with HE staining showed that hepatocyte steatosis was obviously relieved with smaller lipid droplet in LPS pretreatment group than in liver injury group. Conclusions LPS pretreatment can alleviate high-sucrose and high-fat induced NASH. The disequilibrium of Th1/Th2 cytokines may be an important part of mechanism.