Objective： To observe the effects of Danhong Injection （丹红注射液） and its main components, including daiclzein and hydroxysafflor yellow A （HSYA）, on the anticoagulation, fibrinolysis, anti-apoptosis in hypoxia model of vein endothelial cells （VECs）. Methods： VECs were prepared and were put in a hypoxia environment, which consisted of mixed gas of 95% N2 and 5% CO2 mixed gas, when reached confluent culture. Five groups used different treatments, including normal control group, hypoxia group, daiclzein group, HSYA group and Danhong Injection group. The VECs were identified by fluorescence double labeling methods. The morphology was observed by a phase contrast microscopy. The effects of Danhong Injection, daiclzein and HSYA on 6 keto prostaglandin F1α （6-keto-PGF1 α） level was measured by the method of radioimmunoassay （RIA）. Superoxide dismutase （SOD） activity was tested by water soluble tetrazolium salt. The content of malondialdehyde （MDA） was measured by thiobarbituric acid. The activities of tissue-type plasminogen activator （t-PA） and plasminogen activator inhibitor （PAl） were measured by the method of chromogenic substrate. The contents of endothelin （ET） and nitric oxide （NO） were detected by non-equilibrium RIA and enzyme- linked immunosorbent assay. Cells apoptosis rate was determined by flow cytometry. Results： Compared with the normal control group, the floating cells number, PAl activity, ET and MDA contents, and cells apoptosis rate in the culture solution of hypoxia group were all significantly increased, whereas the 6-keto-PGF1 α and NO contents, and t-PA and SOD activities were decreased significantly （P〈0.01）. Compared with the hypoxia group, Danhong Injection markedly increased the 6-keto-PGF1 α content and SOD activity, regulated PAl and t-PA activities, ET and NO contents, and decreased MDA content and cells apoptosis rate （P〈0.05 or P〈0.01）. Conclusions： Danhong Injection and its main components played an important
