The incidence of diabetes mellitus and its complications, including diabetic keratopathy, was significantly elevated with the improved living standards in China recently. Diabetic keratopathy mainly exhibited several clinical features, including the delay of corneal epithelial regeneration, the decreasing of corneal sensitivity, neurotrophic corneal ulcers. The features were mainly caused by the changes of corneal epithelial basement membrane compositions, glycation products deposition, corneal nerve ending damage, reduced tear secretion and oxidative stress in the hyperglycemic conditions. This review focuses on the progress of molecular and cellular mechanism related with the clinical features, and discusses the main problems in the basic research of diabetic keratopathy.