To clerify the antioxidant effect of Crataegi Fructus (CF) extract on reactive oxygen species (ROS), The C6 glioma cells were treated with various concentrations of hydrogen peroxide ($H_2O_2$). The $H_2O_2$-induced neurotoxicity was measured by XTT assay for the cell viability. For the protective effect of CF extract on the cytotoxicity induced by $H_2O_2$, cell viability, lactate dehydroganase (LDH) activity, and the inhibitive activity of lipid peroxidation of CF extract were performed. In this study, $H_2O_2$ decreased cell viability dose- and time-dependent manners and increased LDH activity compared with the control. In the protective effect on $H_2O_2$, CF extract increased cell viability and decreased LDH activity on $H_2O_2$-induced cytotoxicity, lipid peroxidation by FTC assay. From these results, It is suggested that $H_2O_2$ was highly toxic on cultured C6 glioma cells, and also, CF extract showed the protective effect on $H_2O_2$-mediated cytotoxicity.