The purpose of this study was to identify the protective effect of Codonopis pilosula extract on cell death induced by $H_2O_2$ in SK-N-MC neuroblastoma cells. We measured the antioxidant effect by DPPH radical scavenging analysis, BSA analyssis and examined the cell viability by crystal violet and cytochrome C, Bax, Bcl-2, p53, p21 by using Western blot analysis. Codonopis pilosula extract scavenged DPPH radical in a dose-dependent manner and shown direct free radical scavenging effect, suggested that Codonopis pilosula extract have antioxidant effect in vitro. Treatment of cells with hydrogen peroxide, a reactive oxygen species, was to induce cell death and pretreatment with Codonopis pilosula extract attenuated the occurrence of $H_2O_2-induced$ cell death. To elucidate the protective mechanisms of action of Codonopis pilosula extract, Western blot analyses for Bcl-2 and Bax expression and cytochrome c release were carried out. Pretreatment with Codonopis pilosula extract induced the expression of Bcl-2 and suppressed the release of cytochrome c and Bax into the cytosol, thereby arresting $H_2O_2-induced$ apoptotic cell death. Especially p21 and p53 were decreased prior to $H_2O_2$ treatment. These results suggest that Codonopis pilosula extract is associated with the cell cycle and anti-apoptotic cell death.