·AIM:To evaluate the erythropoietin(EPO)expression in the eye of murine model of oxygen-induced retinopathy(OIR).·METHODS:Totally 20 neonates of C57BL/6 mouse were randomly divided into experiment group(n=10)and control group(n=10),for establishing the OIR model,the pups in the experiment group were exposed to 75±5mL/L oxygen since their postnatal day 7(P7)for 5 days and then to room air(pO2=20±1mL/L)with their nursing dams.The neonates in the control group were kept in the room air condition.All of the pups were sacrificed at P17,their right eyes were made into pathological sections for observing and counting the number of vascular cell nuclei on the vitreal side of the internal limiting membrane.And radioimmunoassay was used to compare the EPO content of the retina tissue in the left eye of the pups in the experiment group and the control group.·RESULTS:The histopathological sections of retina showed the retinal neovascularization(RNV)endothelial nuclei were 80.0±6.2 in the neonates after induced by oxygen and 1.0±0.9 in the neonates growing up in normal air.There was significant difference between those two groups(P<0.01).EPO radioimmunoassay indicated that the EPO content in experiment group was 80.8±20.7U/L,but 14.4±6.8U/L in the control group,it showed significant difference(P<0.01).A significant correlation between EPO content and neovascular endothelial nuclei was noted in the experiment group and control group(r=0.58,P<0.01).·CONCLUSION:The RNV can be successfully established by the murine model of OIR.RNV was associated with the EPO high expression of the eye.·