Abstract: Objective To study the protective efficacy of ischemic post-conditioning on ischemic reperfusion injuries of rat liver graft and determine the possible mechanism.Methods The model of orthotopic liver transplantation was established in Sprague Dawley (SD) rats. 48 healthy male rats were randomly assigned into ischemic reperfusion injury group and ischemic post-conditioning group. There was no special care given to ischemic reperfusion injury group before or after donor liver was implanted, however several brief ischemic reperfusions were given for ischemic post-conditioning group before portal vein was completely re-canalized. Half the recipients of the two groups (n=6) were sacrificed in two hours after reperfusion. Liver function tests, tumor necrosis factor-α (TNF α) and neutrophil elastase (NE) in serum and the contents of superoxide dismutase (SOD) and malondialdehyde (MDA) in hepatic tissue were measured. Other six recipients were sacrificed in six hours after reperfusion and hepatic tissue sections were observed with light microscope. Results Liver function tests, cytokines and peroxide product contents of ischemic post-conditioning group were much smaller than that of ischemic reperfusion injury group. The antioxidase content in hepatic tissue of ischemic post-conditioning group was significantly higher than that of ischemic reperfusion injury group. The pathological change of ischemic post-conditioning group was slighter and significantly different from the ischemic reperfusion injury group.Conclusion Ischemic post-conditioning reduces the ischemic reperfusion injury of rat liver graft by decreasing the production of oxygen free radical and restraining the synthesis and release of TNF α and NE.