Abstract: Objective: To observe the protective effect of Shenmai on the myocardial ischemic injury in mice.Methods: The experimental animals were divided into two groups randomly.In the Shenmai group,the mice were injected Shenmai intraperitoneally twice a day(0.2 ml/10g,ip).In the ischemic group,the mice were given normal saline twice a day(0.2 ml/10g,ip).Three days later,pituitrin(20 u/kg) was injected intraperitoneally to induce myocardial ischemic injury.The electrocardiogram was recorded.Results: Shenmai injection reduced the rise amplitude of J spot in electrocardiogram(P<0.01).The heart rate of Shenmai group did not significantly slow down(P< 0.01).Conclusions: These results demonstrate that Shenmai injection can protect myocardium from ischemic injury.