Background Previous research indicated that the development of diabetic retinopathy ( DR) is closely related to the excessive expression of growth factors. This paper was to study the relationship of DR with vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and the retinal vascular pathological change.Methods Fifty-five Wistar rats, weighing 100 -200 g, were selected and randomly divided into four groups: control group (no streptozocin injection, n =10), M1 group (streptozocin induced diabetes for 1 month, n =15), M3 group (streptozocin induced diabetes for 3 months, n =15), and M5 group (streptozocin induced diabetes for 5 months, n =15). In situ hybridization and immunohistochemistry were used to investigate the expressions of bFGF and VEGF on retinal vascular, and retinal vessels were observed by transmission electron microscope.Results There was no difference in the number of pericytes between M1 and control group (P > 0. 05), but the number of pericytes decreased obvi Background Previous research indicated that the development of diabetic retinopathy (DR) is closely related to the excessive expression of growth factors. This paper was to study the relationship of DR with vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and the retinal vascular pathological change. Fifty-five Wistar rats, weighing 100 -200 g, were selected and randomly divided into four groups: control group (no streptozocin injection, n = 10), M1 group (streptozocin induced diabetes for 1 month, n = 15), M3 group (streptozocin induced diabetes for 3 months, n = 15), and M5 group (streptozocin induced diabetes for 5 months, n = 15). In situ hybridization and immunohistochemistry were used to investigate the expressions of bFGF and VEGF on retinal vascular, and retinal vessels were observed by transmission electron microscope. Results There was no difference in the number of pericytes between M1 and control group (P> 0.05), but the number of pericy tes decreased obvi