Abstract： Objective To investigate the histological changes of the internal limiting membrane (ILM) in pathological myopic eyes, and the relationships between those changes and the formation of macular hole. Methods The clinical data of 34 patients (34 eyes)with pathological myopia and maeular hole, who had undergone vitrectomy were retrospectively analyzed. All the patients had a diopter over--6.00 D, their ocular axial length ranged from 26.00 to 33.12 mm with an average of 27.74 mm. There were 5 eyes without retinal detachment (macular hole group)while the other 29 eyes all had posterior retinal detachment (RD group). A standard three-port pars plana vitrectomy was performed in all eyes. The existence of Weiss ring was considered as the sign of posterior vitreous detachment. The epiretinal membranes from 34 eyes and ILM specimens from 19 eyes were stained by hematoxylin-eosin (HE) and acetate urany[ acetate-lead citrate, and then investigated under optical microscope and transmission electron microscope. Results The Weiss ring was observed in 5 eyes during the surgery, multilayer of vitreous tissue resides on the retinal surface in 24 eyes. The results of optical microscope showed that the epiretinal membranes were composed of vitreous collagen, astrocytes and extracellular matrixes. The results from transmission electron microscope showed a sandwich structure (ILM-vitreous collagen-cells) in 5 eyes, and ILM damage, surface traction and astrocytes migration in 1 eye. Conclusions Splitting of posterior surface of vitreous and surface structure change of ILM are the major mechanisms for the formation and progression of macular holes, and even retinal detachment in high myopic eyes.