Objective: To study the effect of Xiongshao Capsule (芎芍胶囊, XSC), a TCM herb that can promote blood circulation to remove blood stasis, on the endothelial dependent relaxation function, serum nitric oxide (NO), and plasma endothelin-1 (ET-1) of the patients with cervical atherosclerosis. Methods: Forty patients were randomly divided into two groups: XSC group and Probucol group (western medicine control).In addition, 20 healthy people were set as a normal control group. Plasma ET-1, serum NO, the internal diameter of basal brachial artery, endothelial dependent flow mediated dilation (FMD) and non-endothelial dependent nitroglycerin induced dilation (NID) to the trial group before and after therapy and to the healthy control group were determined respectively. Results: Compared to the healthy control group, FMD of patients with atherosclerosis was damaged obviously, the serum NO level decreased, plasma ET-1 increased (P＜0.01), NID also decreased (P＜0.05), the internal diameter of basal brachial artery has no obvious difference (P＞0.05). After the patients with atherosclerosis were treated with Xiongshao Capsule for 12 weeks,FMD increased evidently, plasma ET-1 decreased, serum NO and the ratio of NO/ET-1 increased, compared with the level before therapy and Probucol group, the difference was significant (P＜0.05, P＜0.01), NIDdidn′t change obviously (P＞0.05). Conclusion: XSC could regulate vascular activity factor and improve the function of endothelial dependent vascular dilation of patients with atherosclerosis.