Objective To explore the effect of elevated intraocular pressure (IOP) on retina's function of rat. Method Chronic glaucoma rat models were built and IOP were measured persistently. Flash electroretinogram (FERG) and histological status were measured before and after surgery. ResultsThe maximal IOP in rats without anesthesia is (3.07±1.10) kPa in 1 day after surgery. From 1 w to 6 w after surgery, the modeleyeIOPs are （2.84±0.90） kPa，（2.86±0.54） kPa，（2.76±0.52） kPa，（2.70±0.51） kPa，（2.39±0.27） kPa and（2.09±0.39） kPa, respectively, which are significant higher than that of the fellow eye. A series of main parameters including the amplitudes of awave, bwave and oscillatory potentials(OPs) all dramatically decreased in model eyes at 6 weeks and 3 weeks postoperatively . No obvious changes were observed by routine HE staining among the eyes before and after surgery. Conclusions The chronic high intraocular pressure could induce the retinal dysfunction before any morphological change occurred, and what's more, the damage showed itself a progressive one.