The content of MDA and the activity of creatine phosphokinase (CPK) together with the ultrastructural changes in myocardial tissue were analysed to observe the effects of glycyrrhisin on myocardial ischemia/reperfusion injury in rabbits. The results showed that glycyrrhisin could remarkably reduced the level of MDA and the activity of CPK in myocardial tissue (P < 0.01), and mitigated significantly the myocrdial ultrastructural injury in comparison with ischemia/reperfusion group. It was considered that glycyrrhisin exerted obvious protective effects on myocardial injury induced by ischemia/reperfusion.