Aim To evaluate the effect and explore the mechanism of the Compound Salvia Miltiorrhiza Bunge Injection on the vascular endothelium-dependent vasodilatation in patienents with CHD. Methods 84 patienents were randomly divided into three groups(n=28): all patienents were given basic therapy according to the therapeutic guide of CHD, while the two therapeutic groups were respectively added the Compound Salvia Miltiorrhiza Bunge Injection and VitC. We examined the baseline(D 0) and the flow-mediated vasodilation (FMD) of brachial artery by high-resolution ultrasound technique and drew blood to examine the concentration of ET-1,NO and the expression of ET-1 and eNOS mRNA before experiment and after three week’s therapy. The expanding percentage of the flow-mediated vasodilation(FMD) of brachial artery represented the endothelium-dependent vasodilatation(EDD) [EDD=(FMD-D0)/D0×100%]. Results Three groups had no significant difference in D 0, FMD and EDD of brachial artery before experiment. But the EDD of two therapeutic groups improved notably after three weeks’ therapy, and the Compound Salvia Miltiorrhiza Bunge Injection group was better than VitC group. There was no difference of ET-1 and NO among three groups before experiment. After three week’s therapy, the compound salvia miltiorrhiza bunge injection group showed decreasing in the concentration of ET-1 and expression of ET-1 mRNA,increasing in the concentration of NO and expression of eNOS mRNA, all that were significantly different from that of the control group(p<0.05). The VitC group also showed increasing in the concentration of NO and expression of eNOS mRNA, but lower than that of the Compound Salvia Miltiorrhiza Bunge Injection group(p<0.05). Conclusion The Compound Salvia Miltiorrhiza Bunge Injection could improve the brachial endothelial function of CHD patients by regulating the expressions of ET-1 and eNOS mRNA.