The death of retinal ganglion cel s is a hal mark of many optic neurodegenerative diseases such as glaucoma and retinopathy. Oxidative stress is one of the major reasons to cause the cel death. Oligomeric proanthocyanidin has many health beneficial effects including antioxidative and neuro-protective actions. Here we tested whether oligomeric proanthocyanidin may protect retinal glion cel s against oxidative stress induced-apoptosis in vitro. Retinal ganglion cel s were treated with hydrogen peroxide with or without oligomeric proanthocyanidin. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that treating retinal ganglion cel line RGC-5 cel s with 20 μmol/L oligomeric proanthocyanidin significantly decreased the hydrogen peroxide (H 2 O 2 ) induced death. Results of flow cytometry and Hoechst staining demonstrated that the death of RGC-5 cel s was mainly caused by cel apoptosis. We further found that expression of pro-apoptotic Bax and caspase-3 were significantly decreased while anti-apoptotic Bcl-2 was greatly increased in H 2 O 2 damaged RGC-5 cel s with oligomeric proanthocyanidin by western blot assay. Furthermore, in retinal explant culture, the number of surviving retinal ganglion cel s in H 2 O 2-damaged retinal ganglion cel s with oligomeric proanthocyanidin was significantly increased. Our studies thus demonstrate that oligomeric proanthocyanidin can protect oxidative stress-injured retinal ganglion cel s by inhibiting apoptotic process.