Objective To study the defects of bone marrow-derived endothelial progenitor cells (EPCs) in number ratio and biological abilities (proliferation, adhesion and migration) in diabetic rats. Methods (1) Establishment of diabetic rat model:1%STZ solution was quickly injected into the abdominal cavity of the male SD rats with the dose of 60 mg/kg. (2). Isolation, culture and identification of bone marrow-derived EPCs in diabetic and normal rats. Bone marrow mononuclear cells were isolated from diabetic and normal rats by density gradient centrifugation methods and cultured by EGM-2 MV medium. The cells were identified by morphological observation, FITC-UEA-1 binding and Dil-Ac-LDL uptake assay, and fluorescent immunocytochemistry was used for detection of CD34 , CD133 and VEGFR-2 expression. CCK-8 method and Transwell kit method were used to determine biological activities of EPCs. Results (1) When cultured in vitro, both bone marrow-derived EPCs in diabetic and normal rats were fusiform in shape, the cells snuggled up to the wall. The expression of CD34, CDl33, VEGFR-2 could be detected in these cells, and the cells could uptake Dil-Ac-LDL and bind FITC-UEA-1, which proved that these cells were EPCs. (2) No significant difference in the number of EPCs derived from bone marrow existed between diabetic rats and normal rats, but the proliferation ability, migration ability and adhesion ability of bone marrow-derived EPCs in diabetic rats were obviously lower than those in normal rats. Conclusion The number of bone marrow-derived EPCs in diabetic rats is not obviously different from that in normal rats, but the biologic activity of EPCs derived from bone marrow in diabetic rats is degraded, which is manifested as weakened abilities of the proliferation, adhesion and migration.