AIM:To discuss the mechanism,prevention and therapy of the scleral melting after pterygium excision with intraoperative application of mitomycin C(MMC).METHODS:Ten eyes with scleral melting after pterygium excision with MMC were followed up and treated with topical medicine or surgery.RESULTS:The ischemic,thinning could be found at the tissue where the pterygium was excised,and the deep pigment tissue appeared in some patients.The topical medicine and surgery were adopted according to the severity of melting.No recurrences were found during the follow-up.CONCLUSION:To reduce the recurrences after the pterygium excision,the assistant MMC treatment can be adopted,but the concentration and the duration of application should be considered,and the overdose of cauterization should be avoided to assure the enough blood supply at the wound.