OBJECTIVE： To study the protective effect of the injection of puerarin combined with salvianoli acid B （Sal B） on rats with myocardial ischemia reperfusion injury （MIRI）. METHODS： 62 rats were randomly divided into sham operation group， model group， puerarin group （20 mg/kg） and puerarin （20 mg/kg）-Sal B group （mass ratio of 1 ∶ 0.5， 1 ∶ 1， 1 ∶ 2， respectively）， 10 in each group. Except for sham operation group， rats in other groups were reduced for MIRI model. After 180 min of reperfusion， kinase （CK）， lactate dehydrogenase （LDH）， superoxide dismutase （SOD）， malondialdehyde （MDA） in serum and percentage of myocardial infarction size of rats were detected. RESULTS： Compared with sham operation group， CK， LDH， MDA levels in serum of rats in model group were obviously increased （P＜0.01）， SOD level was obviously decreased （P＜0.01）； and percentage of myocardial infarction size was obviously increased （P＜0.01）. Compared with model group， CK， LDH， MDA levels in serum of rats in each administration group were decreased （P＜0.05 or P＜0.01）， SOD levels were obviously increased （P＜0.05 or P＜0.01）， and indexes changed the most obviously in puerarin-Sal B group （1 ∶ 1）； percentage of myocardial infarction size was obviously decreased （P＜0.01）， and the percentage of myocardial infarction sizes in puerarin-Sal B group （1 ∶ 1） and group （1 ∶ 2） were less than Puerarin injection group （P＜0.01）. CONCLUSIONS： Compared with Puerarin injection alone， puerarin combined with Sal B by injection can more effectively inhibit the cardiomyocyte injury and decrease myocardial infarction size after MIRI， with best efficacy when quality ratio is 1 ∶ 1.