Objective:To sudy the effect of Salvia miltiorrhiza extract on heart rate and myocardial enzyme after myocardial ischemia/reperfusion injury in rats.Method:The SD rats were randomly divided into six groups（n=8

each）:sham-operation group

model group

S.miltiorrhiza extract 12.8

6.3

3.2 mg·kg-1 groups and S.miltiorrhiza injection 4×103 mg·kg-1 groups.The myocardial ischemia/reperfusion injury animal model was established by ligaturing left ventricular branch of coronary artery for 30 min and reperfusion for 30 min.The S.miltiorrhiza extract at 12.8

6.4

3.2 mg·kg-1and S.miltiorrhiza injection at crude drug 4.0 g·kg-1were injected by femoral vein after 25 min myocardial ischemia and before 5 min reperfusion

and observing the changes of heart rate and myocardial enzyme.Result:S.miltiorrhiza extract significantly inhibited the decrease of heart rate and reduced serum aspartate transaminase（AST）

lactate dehydrogenase（LDH） and creatine kinase（CK） activity after myocardial ischemia/reperfusion injury in rats.Conclusion:S.miltiorrhiza extract can protect myocardial ischemia/reperfusion injury.