Objective：This study aims to investigate effects and mechanisms of simvastatin pretreatment on liver function in HCC patients undergoing Pringle’s hepatectomy. Methods：Total 73 HCC patients were randomly divided into control group（n=35）and simvastatin pretreatment group（patients were given oral simvastatin 20 mg/d，n=38）. Pre-hepatectomy hepatic biopsies were harvested after laparotomy（prior to hepatic portal occlusion），and post-hepatectomy hepatic biopsies were obtained after reperfusion（prior to abdominal closure）. Serum was collected before operation（Pre-Op）and on the first day after operation（POD-1）. Serum alanine aminotransferase（ALT），aspartate aminotransferase（AST），total bilirubin（TBIL）and albumin（ALB）were measured to evaluate liver injury，and the levels of inflammatory cytokines interleukin（IL）-1，IL-6，inducible nitric oxide synthase（INOS）and tumor necrosis factor（TNF）-α were analyzed by reverse transcriptase polymerase chain reaction（RT-PCR）. The levels of serum malondialdehyde（MDA） and superoxide dismutase（SOD） were detected by kits according to the manufacturer’s directions. Endoplasmic reticulum stress-related protein C/EBP-homologous protein（CHOP） was analyzed by Western blot. Results：The serum levels of ALT，AST and TBIL in POD-1 were significantly lower in simvastatin group than those in control group（P < 0.05），and RT-PCR results showed the levels of IL-1，IL-6，INOS and TNF-α， were significantly lower in simvastatin group than those in control group（P < 0.05）. Furthermore，serum MDA was lower in simvastatin group than that in control group（P < 0.05）；SOD in simvastatin group was significantly higher than that in control group（P < 0.05）. Western blot results displayed that the expression of CHOP was lower in simvastatin group than in control group. Conclusion：Simvastatin pretreatment for HCC patient effectively alleviates liver injury after Pringle’s hepatectomy，and its mechanism could be related to the inhibition of oxidative stress and endoplasmic reticulum stress.