As a newly discovered endogenous regulator, fibroblast growth factor 21(FGF21)becomes hot topic in recent professional research. It plays an important role in diabetic retinopathy recently. Moreover, FGF21 has attracted more and more attention in recent years. This paper discussed the molecular structure of FGF 21, biological function, relationship between FGF21 and inflammatory response and role in the pathological process of diabetic retinopathy.