Abstract: OBJECTIVE To explore the protective effect of Rumex gmelini Turcz. different solvent fractions on acute myocardial ischemia injury induced by isoproterenol in mice and its possible mechanism. METHODS A systematic solvent extraction of 80% ethanol extract Rumex gmelini Turcz. by ethyl acetate part, n-butanol and water extract. Myocardial ischemia model was made by subcutaneous injection of isoproterenol, the content of creatine kinase(CK), lactate dehydrogenase(LDH) and aspartate aminotransferase(AST) in serum and activity of the super oxide dismutase(SOD) and content of malondialdehyde(MDA) in myocardial tissue homogenate were detected, the extent of myocardial damage was evaluated with ST segment in lend Ⅱ on ECG, myocardial water content(MWC) and myocardial index(MI). The degree of myocardial ischemic injury in mice was observed by HE staining. RESULTS The ethyl acetate extract and water extract of Rumex gmelini Turcz. could significantly prolong the survival time of mice atmospheric oxygen. The raise resistance to the ability of acute hypoxia, the content of serum CK, LDH and AST were decreased significantly in ethyl acetate extract and water extract with those in the model group, the activities of SOD was increased, the content of MDA was lowered in myocardial tissue homogenate. CONCLUSION The ethyl acetate extract and water extract of Rumex gmelini Turcz. play a protective role in myocardial ischemia in mice, the protective effect mechanism may be related to its inhibition of the oxygen free radical and enhance oxidation resistance.