Aim To investigate the changes in the number and function of endothelial progenitor cells(EPC) from peripheral blood in patients with low extremity arteriosclerosis disease(LEAD). Methods Sixty cases were divided into LEAD group(n=30) and control group(n=30).Mononuclear cells(MNC) were isolated from peripheral blood by density gradient centrifugation.After 7 days induced diferentiation,the adherent cells were identified as EPC by fluorescein staining and flow cytometry.EPCs's number,proliferation,migration and adhesion were assayed by Giemsa's staining,MTT chromatometry,modified Boyden chamber assay and adhesion activity assay. Results The number of EPC was significantly reduced in patients with LEAD compared with control group(27.2±3.6∶52.6±5.9,Cells/×200 fields,P><0.05) and the number of cell clusters was also reduced in patients with LEAD compared with control group(16.6 ±4.8∶22.3±4.9,CFU/×40 fields,P><0.05).In addition,the proliferation(0.193±0.064∶0.243±0.078,P><0.05),migration(12.1±2.7∶17.8±4.2,Cells/×200 fields,P><0.05) and adhesion(47.3±4.3∶51.9±3.7,Cells/×200 fields,P><0.05) in patients with low extremity arteriosclerosis disease were impaired respectively. Conclusion EPC number and function are abnormally decreased in patients with low extremity arteriosclerosis disease.