AIM: To investigate the effects and mechanism of silibinin(Sil)on rats with alcoholic fatty liver. METHODS: The animal models with alcoholic fatty liver were prepared in rats by feeding on high caloric food and drinking 10% alcohol qd for 10 weeks; after 6-week treatment, the effects of Sil (intragastrointestinally treated 100 mg·kg -1, qd for 4 weeks) were observed by serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP), and serum contents of total cholesterols (TC) , triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β 1, and the contents of TG, malondialdehyde (MDA), glutathione (GSH), and activity of superoxide dismutase (SOD) in the hepatic tissue. Hepatic histopathology was observed by microscope. RESULTS: Serum levels of ALT, AST and AKP decreased in administration of Sil (P< 0.05 or 0.01), the levels of TG, LDL-C, TNF-α and TGF-β 1 reduced (P< 0.05 or 0.01), the concentrations of TG and MDA in the hepatic tissue lowered (P< 0.01), and the activity of SOD potentiated (P< 0.01). Hydropic and/or fatty degeneration of hepatocytes were improved (P< 0.01). CONCLUSION: Silibinin can preclude alcoholic fatty liver in rats from drinking alcohol and feeding high caloric food, and pharmacological mechanisms were involved in anti-oxidation and removing free radical, inhibiting lipid peroxidation, adapting blood lipid component, reducing fatty sediment in liver, anti-inflammation and anti-hyperplasia.