To study the changes of microcirculation in patients with diabetic retinopathy (DR).Examination were performed in 153 cases of type I diabetes mellitus, among them, 72 cases were male, 81 cases were female, mean age 57.0+/-10.0 years, mean disease course 8.2+/-7.5 years. All cases were examined fundi by ophthalmologist, urinary albumin excretion rate (UAE) in 24 hours was measured by radioimmunoassay. Moreover, we examined the blood glucose, blood pressure, blood viscosity and observed the changes of naifold microcirculation.It was found that there were more evident disturbance of microcirculation, markedly slowed velocity of blood flow (P<0.05), significantly increased aggregation of blood cells (P<0.05) and exudation around the loop (P<0.05) in the group with DR, compared with the group without DR.It was more evident disturbance of nailfold microcirculation in patients with diabetic retinopathy.