Abstract: Exosomes are nanoscale microvesicles secreted into the extracellular matrix after the fusion of intracellular polycystic bodies with the plasma membranes. They are widely distributed in biological tissues and body fluids, and play an important role in the secretion defects of islet β cells and insulin resistance, which are two critical pathogenic factors of diabetes. They are also involved in the occurrence and development of diabetes and its extraocular complications, such as cardiovascular disease, diabetic nephropathy and diabetic skin damage. Exosomes existing in the eye (vitreous cavity, retinal cells, etc.) and in plasma, can be transmitted in the ocular and systemic circulation in patients with diabetic retinopathy (DR). Exosomes carry some biomolecules related to the pathogenesis of DR, such as fibroblast growth factor, vascular endothelial growth factor, various inflammatory factors, etc. Under the stimulation of high glucose and hypoxia, these molecules are transported and released by exosomes and then activate or inhibit some signal transduction pathways, stimulate the proliferation of vascular endothelial cells and neovascularization of retina in patients with DR, thereby promote the occurrence and progress of DR. Due to the small size and doublemembrane structure, exosomes can target the transport of coated components, which is an efficient drug delivery tool for the treatment of DR in the future.