Aim To discusse the relationship between the number and function of early and late endothelial progenitor cell （EPC） in peripheral blood and the carotid stenosis （CS）. Methods 60 cases were included into the group of objects, and divided into group of 40 patients with carotid artery stenosis （mild stenosis in 20 cases, severe stenosis in 20 cases）, normal control group of 20 cases. The blood was extracted from the patients’ femoral artery in the procedure of cerebrovascular digital subtraction angiography, mononuclear cells were isolated from peripheral blood by density-gradient centrifugation and were cultured for 7 days and 21 days to be identified as early endothelial progenitor cells and late endothelial progenitor cells, colony counting the number of early EPC and late EPC. Proliferation and migration were determined by MTT assay and modified Boyden. The two types of EPCs adhesion assay were performed by replating those on fibronectin-coated dishes, then adherent cells were counted. Results Smoking, high blood pressure and triglycerides, low density lipoprotein in carotid stenosis groups were significantly higher than those in the control group, high-density lipoprotein cholesterol （HDLC） was lower than those of the control group （P<0.05） the difference of age, sex, blood sugar, total cholesterol compared with controls, was not statistically significant （P>0.05）. Compared with controls, the number and function of early EPC, late EPC in carotid stenosis group was decreased, the number and function changes of late EPC were negatively correlated with the degree of cerebral stenosis（P<0.05）. Conclusions Decreased late EPC colonies amount and functional impairment can be observed in patients with carotid artery stenosis. The number and function changes of late EPC were negatively correlated with the degree of cerebral vascular stenosis. Detection of late EPC number and function can be indirect prediction of carotid stenosis severity.