Reperfusion of ischemic liver results in the generation of oxygen radicals. In this study, we analyzed the antioxidants such as superoxide dismutase (SOD) and catalase mRNA and protein expressions after reperfusion liver injury and analyzed the hydrogen peroxide production. Ischemia (I) was induced by clamping the common hepatic artery and portal vein of rats for 40 min and then reperfused (R) for 90 min. Blood samples collected prior to I and after R were analyzed for hydrogen peroxide, aspartate transferase (AST), and alanine transferase (ALT). Liver tissues were used to analyze the SOD and catalase mRNA and protein expressions by real time polymerase chain reaction and Western blot. The results showed that this protocol resulted in elevation of the blood AST and ALT levels (p<0.01), however, hydrogen peroxide decreased (p<0.05). MRNA and protein expressions of SOD and catalase were all increased (p<0.05). Pretreatment of N-acetyl cysteine (NAC) attenuated the liver injury. These results indicate that reperfusion of the ischemic liver induced antioxidant enzymes expressions so that oxygen radicals are scavenged. Oxygen radicals scavenger (NAC) could further attenuates the ischemia/ reperfusion-induced liver injury.