Objective The aim of this study is to evaluate the cytoprotection and potential molecular mechanisms of cyanidin-3-glucoside (C3G) on hydrogen peroxide (H2O2)-induced oxidative damage in HepG2 cells. Methods The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was carried out to examine the viability of HepG2 cells exposure to H(2)O(2)or C3G. Meanwhile, the antioxidant properties of C3G were measured by determining the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and the malondialdehyde (MDA) levels. Flow cytometry was employed to determine HepG2 cells apoptosis, and HepG2 cells were stained with Hoechst 33342 to observe cell morphology. 2 ',7 '-dichlorofluorescin diacetate (DCFH-DA) was used to evaluate the production of intracellular reactive oxygen species (ROS). Finally, the expression of apoptosis-related protein was monitored through western blot analysis. Results HepG2 cells induced with H(2)O(2)presented a remarkable decrease in cell viability that was suppressed when HepG2 cells were interfered with C3G (2.5-10 mu M). C3G interference memorably and dose-dependently inhibited H2O2-induced intracellular ROS and MDA overproduction, while C3G treatment markedly increased H2O2-induced the activities of intracellular SOD, GSH-Px and CAT. Eventually, the relative proteins expression levels of p53, cleaved caspase-9/3, cytochrome c, Fas-L, Fas, FADD and caspase-8 were substantially up-regulated in H2O2-triggered HepG2 cells, and Bax/Bcl-2 ratio and the relative protein expression levels of PARP were dramatically down-regulated. However, the expression levels of these relative proteins were reversed in C3G-interfered HepG2 cells. Conclusions C3G could protect HepG2 cells from oxidative damage, and the effects that were mediated by the mitochondrial apoptotic pathways and the external pathways.