Objective To monitor the development process in diabetic retinopathy (DR) by color Doppler imaging (CDI), retinal vessel digest preparations, and histopathology, and to investigate the relationship between the hemodynamic changes of retina and retinal vessel morphology in diabetic rats. Methods Diabetic rats were induced by ip administration of Streptozotocin. The hemodynamic changes of central retina artery (CRA) of the right eyes of rats in the model group and control group were detected with CDI in diabetic duration of 2, 4, and 6 months, respectively. The right eyes of rats were dissected to make retinal vessel digest preparations to calculate endotheliocyte/perithelial cell ratio, the left eyes of rats were dissected for histopathology tests. Results There was significant difference of CRA hemodynamics between diabetic and normal rats in diabetic duration of two months. In contrast, the loss of pericapillary cells and hyperplasia endothelial as the only early changes of DR were demonstrated in 4 and 6 months diabetic rats in retinal digest preparations. Under the light microscope, the neovascularization, haemorrhage, and effusion in retina interior were observed at this time. Conclusion The results show that the retinal hemodynamics could display abnormal changes and become more serious with the progress of the disease, and suggest that the reduction of retinal blood flow and blood dabbling be important causes of DR in the early stage of diabetes. In the early stage of diabetes, corresponding treatment should be taken before the onset of DR to improve blood supply of the retina, which may postpone or reverse the incidence and development of DR."/>