Objective To observe the protective effect and mechanism of Danhong Injection（丹红注射液）on endothelial function of perioperative unstable angina（UA）patients with blood stasis syndrome undergoing percutaneous coronary intervention（PCI）. Methods Totally 100UA patients with blood stasis syndrome undergoing PCI were randomized into the Danhong group and routine group

with 50in each.Both groups were given conventional treatment 1to 3days before PCI.Danhong group was added with intravenous infusion of 40ml Danhong Injection（丹红注射液）.The administration lasted for 4to 6days in both groups after operation（lasted for 7days in total during the perioperative period）.The levels of superoxide dismutase（SOD）

malondialdehyde（MDA）

von Willebrand factor（vWF）and soluble intercellular adhesion molecule-1（sICAM-1）were detected before and after medication.The flow-mediated dilation（FMD）of brachial artery was detected before PCI and 2days after PCI. Results The SOD level was significantly increased but the levels of MDA

vWF and sICAM-1were significantly decreased in the Danhong group after medication（P<0.05）.The SOD level was significantly decreased but the levels of MDA

vWF and sICAM-1were significantly increased in the routine group after medication（P<0.05）.The levels of FDM were significantly decreased in both groups after medication（P<0.05）

especially in the routine group（P<0.05）. Conclusion Danhong Injection（丹红注射液）can improve the endothelial function after PCI by reducing the endothelial injury of oxidative stress.