Objective To investigate auto-cortex of crystalline lens-induced neovascular epiretinal membrane（NVERM）by micro-injuring posterior c apsule of crystalline lens. Methods twenty four C57BL/6 mouse between 4-6 weeks were selected, and divided into two groups randomly: auto-cortex of crystalline group and the control group. The auto-cortex of crystalline group was treated by penetrating the posterior capsule of lens and washing out the lens cortex into the mouse vitreous using PBS (phosphate buffered solution), while the control group were injected PBS into vitreous merely. Clinical change s were followed by slit-lamp examination and photograph. The eye balls were enu cleated at the day of 3, 7, 14 and 28 after operation. Both HE and immunohistoch emistry were used to detect the pathological changes. Results postoperative one to three days, 11 of 12 mouse in autocortex of crystalline g roup, lens appear to alba turbid at different levels one after another, and then develop into highdensity chinaware white. Postoperative (po) three days, HE s taining shows cortex of lens debris transmigrated in vitreous cavity, and some o f which approached to internal limiting membrane and lead it to rough and discon tinue; Po7-14 days, the capillary in retina expanded, migrated and broke though t internal limiting membrane which got to the pro retina and became the new ves sels. And typical NVERM were observed. Po28 days, some vascularslike structure formed in vitreous cavity. None of mouse in control group developed NVERM. Conclusion Auto-cortex of crystalline lens can induced neovascular epiretinal membrane in C57BL/6 mouse. (Chin J Ocul Fundus Dis,2008,24:118-121)