Objective To observe the effects of naringin (Nar) on hemodynamics in myocardial ischemia-reperfusion(MI/R) injury rats for investigating its protective role on MI/R rats.Methods The ischemia-reperfusion(I/R) model was prepared by ligating the left anterior descending coronary artery,meanwhile different doses of Nar(10,20,40 mg/kg) were given.Then the electrocardiogram (ECG) was recorded after 7 d.The left ventricular end diastolic pressure (LVEDP),left ventricular systolic pressure (LVSP) and maximum ascending rate of left ventricular pressure/maximal descending rate of left ventricular pressure (±dp/dtmax) were measured.The activities of srum creatine kinase (CK) and lactate dehydrogenase (LDH) were measured by using the chemical colorimetry method.Results Compared with the MI/R group,Nar 20,40 mg/kg could decrease LVEDP,increased ±dp/ dtmax and LVSP,and decreased the activities of serum CK and LDH (P＜0.05),showing a dose-dependent manner.Conclusion Nar has the protective effect against MI/R injury rat and alleviates the myocardial damage extent,which may be related with improving the hemodynamics.