Objective: To observe the protective effect of ligustrazine on myocardial ischemia rat induced by isoproterenol. Methods : The model of myocardial ischemia was induced by subtcuaneous injection of isoproterenol (ISP, 5mg?kg -1 ) into rats and repeated the same dose 24 hours later. The activities of Ca 2+ -ATPase、Ca 2+ -Mg 2+ -ATPase and the contents of Ca 2+ in the myocardial mitochondria were observed, respectively. The changes of protein expression of bcl-2 and bax genes were detected by immunohistochemical staining. Results : In the ligustrazine treated group, as compared with those of the model, the activities of Ca 2+ -ATPase、Ca 2+ -Mg 2+ -ATPase in the myocardial mitochondria increased significantly( P 0.05). Conclusion : Ligustrazine possesses protective effects against myocardial ischemia injury via increasing the activities of Ca 2+ -ATPase、Ca 2+ -Mg 2+ -ATPase in the myocardial mitochondria and influencing the expression of bcl-2.