AIM: To investigate the hypothesis that the protective effects of curcumin in hepatic warm ischemia/reperfusion (I/R) injury are associated with increasing heat shock protein 70 (Hsp70) expression and antioxidant enzyme activity.METHODS: Sixty Sprague-Dawley male rats were randomly divided into sham, I/R, C + I/R groups.The model of reduced-size liver warm ischemia and reperfusion was used. Curcumin (50 mg/kg) was administered by injection through a branch of superior mesenteric vein at 30 min before ischemia in C + I/R group. Five rats were used to investigate the survival during 1 wk after operation in each group. Blood samples and liver tissues were obtained in the remaining animals after 3, 12, and 24 h of reperfusion to assess serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver tissue NO2- + NO3-,malondialdehyde (MDA) content, superoxide dismutase(SOD), catalase (CAT), nitricoxide synthase (NOS) and myeloperoxidase (MPO) activity, Hsp70 expression and apoptosis ratio.RESULTS: Compared with I/R group, curcuminpretreatment group showed less ischemia/reperfusioninduced injury. CAT and SOD activity and Hsp70expression increased significantly. A higher rate of apoptosis was observed in I/R group than in C + I/R group, and a significant increase of MDA, NO2- + NO3-and MPO level in liver tissues and serum transaminase concentration was also observed in I/R group compared to C + I/R group. Curcumin also decreased the activity of inducible NO synthase (iNOS) in liver after reperfusion,but had no effect on the level of endothelial NO synthase(eNOS) after reperfusion in liver. The 7 d survival rate was significantly higher in C + I/R group than in I/R group.CONCLUSION: Curcumin has protective effects against hepatic I/R injury. Its mechanism might be related to the overexpression of Hsp70 and antioxidant enzymes.