【Abstract】 Objective Investigate the correlation between circulating endothelial progenitor cells (EPCs) , serum AngII levels, serum Ang17 levels and cognitive function of patients with vascular dementia (VaD).Methods Subjects were divided into VaD group (n= 55) and cognitive normal group (n= 45).The clinical data of subjects were collected. Carotid artery intimamedia thickness (IMT) was measured by carotid ultrasound. The peripheral blood EPCs were detected by flow cytometry. The levels of serum AngII and Ang17 were detected by ELISA. The cognitive function were measured by MMSE scale.Results The numbers of circulating EPCs, serum Ang17 levels and MMSE scores in VaD group were lower than those in normal cognitive group. The levels of serum AngII were higher than those in normal cognitive group. The differences were statistically significant (P＜005). The numbers of circulating EPCs in VaD group were positively correlated with serum Ang17 levels (P＜005), and were negatively correlated with serum AngII levels (P＜005). MMSE scores in VaD group were positively correlated with the numbers of circulating EPCs (P＜005), and were positively correlated with serum Ang17 levels (P＜005), and were negatively correlated with serum AngII levels (P＜005).Conclusion The cognitive function of VaD patients may be related to the numbers of circulating EPCs ,the levels of serum AngII and serum Ang17.