To observe the inhibitive effect of subconjunctival or intravitreal-injecting pigment epithelium-derived factor(PEDF) for retinal neovascularization(RNV) in oxygen-induced animal models. METHODS: Mouse models of oxygen-induced retinopathy of prematurity were established.48 newborn rats were randomly diveded into 6 groups（A：Air control group；B：High oxygen control guoup；C：High oxygen +intravitreal injection of 2μg PEDF group；D：High oxygen+subconjunctival injection of 2μg PEDF group；E：High oxygen+subconjunctival injection of 4μg PEDF group；F：High oxygen+subconjunctival injection of 8μg PEDF group）. When the rats were taken off the high oxygen，the phosphate buffer solution(PBS) and corresponding dosage of PEDF were intravitreally or subconjunctivally injected in group C，D，E and F respectively. ADP-ase stained retinal flat-mounts was used to evaluate the retinal vascular modality and development, eyeball pathological section was used to count the pre-retinal endothelial nucleus in retinal new vessel. Retinal PEDF expression were detected by Western blot. RESULTS: PEDF were achieved in retina after a periocular injection. Retinal flat-mounts: A group: The retina vessels of the normal had a fine radial branching pattern that extended from the optic nerve to the periphery; B group: There were more RNV compared with A group.The density and shape of RNV were disordered; Compared with B group, RNV decreased obviously in C group while-D, E, F group decreased mildly. HE staining: A group: Retinal internal limiting membrane was smooth, and occasionally the endothelial cells broke through the inner retina. B group was significantly more than A group (P<0.05). C group was significantly less than the B group (P<0.05), D, E, F group had significant difference with C group (all P<0.05). CONCLUSION: PEDF are able to penetrate the sclera into retina after a periocular injection，however，compared with intravitreal injection，the effect reduced significantly. How to reach the retina effectively requires further study by subconjunctival injection."" "