AIM: To explore an efficient, practical and objective quantitative method to evaluate the retinal neovascularization in mouse model of oxygen induced retinopathy (OIR). METHODS: Thirty C57BL/6J mice were explored in OIR model procedure. Eyes were removed for different staining methods including: (1) HE staining; (2) immunohistochemistry with Griffonia Simplicifolia Lectin(GSL);(3) Immunofluore- scence with FITC labeled CD31 antibody; (4) Two-step immunofluorescence with purified-CD31 antibody; (5) FITC-Dextran perfusion combined with two-step purified- CD31immunofluorescence. Images of the retinal vasculature were analyzed by imaging software. RESULTS: GSL immunohistochemistry could clearly demonstrate the deep and superficial capillary beds. FITC labeled CD31 Immunofluorescence was blurring with high fluorescence background which was hard to distinguish retinal neovascularization in some area. Excellent detail of neovas- cularization and preexistent retinal vessels was provided in two-step Purified-CD31 immunofluorescence group. CONCLUSION: GSL immunohistochemistry can clearly demonstrate neovascularization tufts in deep and superficial capillary beds. Immunofluorescence of specific antigen CD31 on vascular endothelium can selectively label the neovascularization of mouse retina. When combined with computer analysis software, it is an effective and objective quantitative method to evaluate the retinal neovascularization in OIR mouse model.