It has been suggested that oxidative stress of reactive oxygen species(ROS) may play a key role in the pathogenesis of neuronal complications. The aim of this study was to examine the cytotoxic effect of hydrogen peroxide(H₂O₂) in the cultured mouse cerebral neurons and the protective effect of Schisandrae Fructus(SF) on ROS-induced neurotoxicity. Cytotoxic effect of H₂O₂ and neuroprotective effect of SF were determined by MTT assay. H₂O₂ decreased cell viability in dose-and time-dependent mannner, and SF decreased H₂O₂-induced neurotoxicity in these cultures. From above the results, H₂O₂ has toxic effect, and herb extract, SF is very effective against H₂O₂-induced neurotoxicity in cultured cerebral neurons of mouse.