The aim of this article is to investigate the mechanism of vitexin-4''-O-glucoside (VOG) protecting ECV-304 cells against tertbutyl hydroperoxide (TBHP)-induced injury. ECV-304 cell viability was measured by MTT assay. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) assay. Cellular morphological changes were observed using phase contrast microscopy. The change of relative mitochondrial transmembrane potential in the ECV-304 cells was analysed with rhodamine 123 staining. Lipid peroxidation was measured by the HPLC method. The results showed that 128 µmol L(-1) VOG could effectively protect ECV-304 cells against cytotoxicity induced by TBHP. VOG protected TBHP-treated ECV-304 cells from death, significantly decreased MDA production, and increased superoxide dismutase (SOD) activity and mitochondrial membrane potential (ΔΨ). Taken together, VOG protects against TBHP-induced ECV-304 cell injury partially through resuming mitochondrial function.