Abstract: Objective: To observe the effect of Qili Qiangxin capsules on myocardial injury and vascular endothelial function in patients after percutaneous coronary intervention(PCI). Methods:A total of 70 cases of patients undergoing PCI treatment were randomly divided into the observation group and the control group,35 cases in each group. The control group was treated with conventional western medicine, and the observation group was additionally treated with Qili Qiangxin capsules based on the treatment of the control group. Both groups were treated for six months. The levels of heart function indexes, myocardial injury markers and vascular endothelial function markers before and after treatment as well as the incidence of adverse reactions in the two groups were compared. Results:After treatment,left ventricular ejection fraction (LVEF) in the two groups was increased when compared with that before treatment(P<0.05), and left ventricular enddiastolic diameter(LVEDD) and left ventricular diameter(LVD) were decreased(P<0.05); LVEF in the observation group was higher than that in the control group(P<0.05), and LVEDD and LVD were lower(P<0.05). After treatment, the levels of cardiac troponin I(cTnI) and creatine kinase-MB(CK-MB) in the two groups were increased when compared with those before treatment(P<0.05),and the levels of cTnI and CK-MB in the observation group were lower than those in the control group (P<0.05). After treatment,nitric oxide(NO) levels,flow-mediated dilation(FMD) and nitroglycerin-mediated dilation(NMD) in the two groups were increased when compared with those before treatment(P<0.05),and ET-1 levels were decreased(P< 0.05);NO levels,FMD and NMD in the observation group were higher than those in the control group(P<0.05),and ET-1 level was lower(P<0.05). The incidence of adverse reactions was 8.57% in the observation group,lower than that of 37.14% in the control group(P<0.05). Conclusion: Qili Qiangxin capsules for patients after PCI can effectively improve their heart function,alleviate their myocardial injury,improve their vascular endothelial function,and reduce the incidence of adverse reactions.