Objective To discuss the clinical phases of alkali chemical burn and the criteria of grading for severity of late phase.Methods Fourty-two patients with alkali burn of stable late stage were divided into four grades: mild (Grade Ⅰ), moderate (Grade Ⅱ), severe (Grade Ⅲ) and most severe (Grade Ⅳ). The selection of various operations depended on the grades. In mild patients, vascular membranous tissue and fibrous conjunctiva were resected. Autografts with stem cells and conjunctiva were transplanted simultaneously. Lamella was transplanted routinely using the fresh donor within 24 hours, with stem cells of limbus and corneal epithelium, combined with autograft stem cells of limbus implantation for Grade Ⅱ and Ⅲ. In most severe patients, three procedures were followed: monitoring and controlling intraocular pressure, reconstruction of limbus epithelium, and penetrating keratoplasty (PKP).Results All operations of 4 eyes of Grade Ⅰ were successful. Among 13 eyes of moderate grade, the transplantations of stem cells with antografts, corneal epithelium and lamellae with allografts (66.7% of PKPs) were successful. The visual acuity of 12 eyes was over 0.05. Among 10 eyes of severe grade, the transplantation of stem cells with autografts of 8 eyes was successful (80.0%). PKP of 6 eyes was successful (75.0%). The visual acuity of 9 eyes was over 0.05. Among 15 eyes of most severe grade, 6 were unilateral. The operation of 4 eyes was similar to that of the severe grade and it was successful. For 9 eyes of bilateral burn, stem cells transplantation and PKP with allografts were performed, but failed at 10 months postoperatively. The complications were treated. The visual acuity of 9 eyes was over 0.05.Conclusions The efficacy of late treatment of ocular alkali burn is dependent on several factors: unilateral or bilateral burn, the extent of damaged stem cells and corneal endothelium, the severity of complication. 70.6% of operations of unilateral burn, which was more severe than the moderate, were successful. But the treating result of severe bilateral burn was not satisfactory.