Proliferative diabetic retinopathy(PDR)is a group of disease characterized by neovascular disease complication of diabetes mellitus. Neovascular diseases of eye are one of the major causes of blindness of the world. Recent studies showed that vascular endothelial growth factor(VEGF)and pigment epithelium-derived factor(PEDF)are now accepted as the key cytokine in the development of diabetic retinopathy. Recent progress in the investigation of VEGF and PEDF of PDR are summarized in this review.