Objective To observe the effect of intravitreal injection of mouse nerve growth factor (NGF) on interphotoreceptor retinoid-binding protein (IRBP) in the vitreous of diabetic rats at early stages. Methods Ninety-six male Sprague Dawley (SD) rats were divided into control group (group A, 24 rats) and experimental group (72 rats). The rats in experimental group were induced with streptozotocin injection for diabetic retinopathy model, and then randomly divided into positive control group (group B), normal saline group (group C) and NGF group (group D), 24 rats in each group. The rats in the group A and B were not intervened. The rats were received intravitreal injection with 4mu;l normal saline (group C) or 4 mu;l (0.5 mu;g/mu;l) NGF (group D). At 2, 4, 6 and 8 weeks after injection, IRBP levels were detected by enzymelinked immunosorbent assay (ELISA); hematoxylin-eosin (HE) staining and light microscope were used to observe the morphological changes of the retina; transmission electron microscope was used to observe the retinal ultrastructure.Results At 2 weeks after injection, there was no significant difference in IRBP expression between group A,B,C and D (F=2.833，P=0.052). At 4, 6, 8 weeks after injection, the differences of IRBP expression between group A, B, C and D were significant (F=22.252, 108.459, 105.726; P=0.000). At different time points after injection, there was no significant difference in IRBP expression of group A (F=1.462, P=0.241), but there were significant differences in IRBP expression of group B, C and D (F=150.98, 63.519, 64.604; P=0.000). Light microscope found that the retinal structure was clear in group A and in group B, C, D at 2, 4 weeks after injection; the retinal thickness were thinner in group B, C, D at 8 weeks after injection. Transmission electron microscope displayed that the structure of rod outer segments was clear in group A and in group B, C, D at 2 weeks after injection; partly unclear structure of rod outer segments and slightly enlarged gap were observed in group B, C, D at 4, 8 weeks after injection. Conclusion Intravitreal injection with NGF can stabilize the IRBP expression in the vitreous of diabetic rats at early stages effectively.