Abstract: Objective To investigate the effect of ergonovine pretreatment on ischemia-reperfusion injury of the hepatic grafts in rats. Methods In the auto-orthotopic liver transplantation model of rats,ergonovine was injected via the tail vein of rats 10 min before hepatic portal occlusion. Before is chemia and 5 min,30 min and 2 h after perfusion in the hepatic grafts, changes in serum NO and plasma ET1 levelS and the ratio of NO/ET1 were observed. Serum ALT and contents of ATP and MDA in liver tissues were determined. At 2nd h post-reperfusion,the changes in ultrastructures of hepatocytes and hepatic lobules were examined. Results In the rats pretreated with ergonovine,plasma ET1 levels in portal vein of transplanted liver before ischemia was elevated(P<0.01),but 5 and min after reperfusion,serum ET1 levels were reduced(P<0.05). Before ischemia,the ratio of NO/ET1 was decreased(P<0.01),but that was increased 5 min after reperfusion(P<0.05).After reperfusion,ALT levels had a trend of gradual decrease. Moreover, ergonovine could improve the microculation of transplanted liver with ischemia-reperfusion injury, and alleviate the damage to the hepatic ultrastructures. Conclusions Pretreatment with ergonovine could alleviate the transplanted liver ischemia-reperfusion injury. The ratio of NO/ET1 may be the regulatory factor involved in the blood flow of the transplanted liver microcirculation.