This study was undertaken to elucidate the antioxidant activity of the ethanol (EEPB) and water (WEPB) extracts of Prunus persica branches. The extracts contained a high phenolic content and revealed a potent hydrogen donating activity in DPPH scavenging assay. Compared to $alpha$-tocopherol, EEPB (p < 0.001) and WEPB (p < 0.05) significantly inhibited $FeCl_2$-ascorbic acid-induced lipid peroxidation, and also exhibited potent antiradical activities against hydroxyl radical, superoxide anion, nitric oxide and peroxynitrite. In copper- and AAPH-mediated human low-density lipoprotein (LDL) oxidation systems, the extracts demonstrated a strong antioxidant function by metal chelating, rather than direct scavenging, action. Furthermore, EEPB at 5 ${mu}g/mL$ concentration showed 80.77% inhibition of the electrophoretic mobility of LDL, compared to 77.69% for ascorbic acid and 76.92% for BHT. These results suggest that PB branch extracts may protect against oxidative stress-induced diseases.