AimTo study clinical effects of Shenmai injection on unstable angina and understand its mechanism.Methods178 cases with unstable angina, was divided into treatment group and control group.Treatment group was treated by conventional western medicine plus ShenMai injection.The control group was treated by conventional western medicine plus GIK injection.Observe symptoms of angina and ECG remission situation and detect the plasma tissue factor pathway inhibitor-2 concentration before and after treatment.ResultsThe clinical baseline was similar.Symptom remission rates of treatment group and control group were 84.3%, 69.7%;ECG improvement rates was 74.5%,61.8%.There were significant differences (p<0.05).The plasma tissue factor pathway inhibitor-2 declined after treatment.But the treatment group decreased more significantly; the difference was significant (p<0.01).ConclusionsThe Shenmai injection plus the conventional western medicine can effectively alleviate the unstable angina.Its treatment effect may be related to the changes of tissue factor pathway inhibitor-2.