OBJECTIVE： To study the effects of carbamylated erythropoietin （CEPO） on cardiovascular microcirculation in rats with diabetes mellitus. METHODS： Rats were randomly divided into blank control group， model group， CEPO low-dose， medium-dose and high-dose groups （500， 1 000， 2 000 u/kg） with 12 in each group. The rats in the last 4 groups were reduced diabetes mellitus model. All rats were given relevant medicine intragastrically twice a week， coronary microcirculation endothelial cells were separated after consecutive 4 weeks. Enzyme-linked immunosorbent assay was conducted to detect levels of peripheral serum prostacyclin （PGI2）， vasoconstrictor endothelin-1 （ET-1）， angiotensin Ⅱ （AngⅡ） and von Willebrand factor （vWF） of rats in each group； in vitro CCK 8 test was used to detect endothelial cell activity （OD value）； real-time quantitative polymerase chain reaction was adopted to detect proliferation-related genes （Ki67， p16）， poptosis-related genes （Bad， Bax）， and expressions of protein vascular endothelial growth factor （VEGF） and AngⅠ. RESULTS： Compared with blank control group， levels of PGI2， ET-1， AngⅡ and vWF in serum in model group increased； OD value deceased； Ki67， p16， Bax and VEGF expression decreased； the difference was statistically significant （P＜0.05）. Compared with model group， levels of PGI2， ET-1， AngⅡ and vWF in serum in CEPO low-dose， medium-dose and high-dose groups increased； OD value increased； Ki67， p16 and VEGF expression increased； expressions of Bad and Bax decreased； the difference was statistically significant （P＜0.05）. The others had no significant difference （P＞0.05）. CONCLUSIONS： CEPO maybe improve the coronary microcirculation function by upregulating VEGF expression in coronary microcirculation endothelial cells and promoting endothelial cells’ regeneration.