Objective To investigate the effect of proanthocyanidins (PC) on retina of rats with acute ocular hypertension. Methods The SpraqueDawley (SD) rats were randomly divided into the normal group, the model group and PC high or lowdosage group. The PC high or low dose group received 300mg/kg.d or 100mg/kg.d of PC in suspension solution for 5 days respectively. The normal group and the model group fed with distilled water for 5 days. Then acute ocular hypertension was induced in the model group and all PC groups, and after 48h of ocular hypertension the eyeballs were analyzed by electron microscope and UV spectrophotometer to measure the levels of superoxide dismutase(SOD), malonaldehyde (MDA), nitrogen monoxidum (NO), glutamic acid (Glu) and calcium ion(Ca2+). Results PC could raise the activity of SOD and reduced the levels of MDA,NO,Glu and Ca2+ in retina tissue. Electron microscope examination revealed that PC reduced retinal edema and ganglion cell apoptosis. PC also enhanced the SOD activity and suppressed the levels of MDA, NO, Glu and Ca2+. Conclusions PC can protect retina from acute ocular hypertension. The main mechanism might relate to anti-free radical oxidation, antagonizing calcium overloading, reducing toxicity of NO and Glu on the retina.