Aim To investigate the protective effect of proanthocyanidins(PC) on the injury of vascular endothelial cell(VEC) induced by hydrogen peroxide and its corresponding mechanisms.Methods The endothelial cell strain from human umbilical vein was cultured and a model of VEC injured by hydrogen peroxide(H2O2) was established.This study was conducted as follows:normal control group,H2O2-injury group(250 μmol/L),PC protective groups(25,50,100 mg/L).Cell viability was tested by using MTT.The levels of malondialdehyde(MDA),superoxide dismutase(SOD) and lactate dehydrogense(LDH) activity were measured with corresponding kit.H2O2-induced apoptosis was detected using staining with Hoechst 33258.Protein levels were examined by Western-blot.Results PC could inhibit the hydrogen peroxide induced VEC reduction,suppress LDH activity,reduce the MDA production,and enthance SOD activity under hydrogen peroxide.Typical apoptotic cells were detected using staining with Hoechst 3325.The bcl-2 protein expression increased.Conclusions These results demonstrated that PC can protect the VECs from H2O2-induced injury,and the possible mechanism may refer to its effect of anti-apoptosis,anti-lipid peroxidation and SOD activity enhancing.