The objective of this study was to investigate the protective effects of mulberry (Morus alba) sugar extracts (MSE) against H 2 O 2-induced oxidative stress in HepG2 cells. The MSEs was mixed with matured mulberry and sugar at the same ratio (1:1, w/w) and stored at 18±3℃ for 40 days. In 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging test, MSE stored for 40 days showed high activity with a ratio above 66%. Therefore, we selected 40 days as the optimum storage period. After cell viability analysis using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, we determined that the optimum concentration of MSE was 0.5%. Our results showed that MSE increased the cell viability and antioxidant enzyme activities of superoxide dismutase (SOD) and catalase in H 2 O 2-treated HepG2 cells. Moreover, the treatment with MSE inhibited malondialdehyde (MDA) levels in H 2 O 2-treated HepG2 cells. We also observed a reduction in apoptotic bodies in the Hoechst staining. These data show that MSE treatment significantly suppressed caspase-3 activity in HepG2 cells expored to H 2 O 2-induced oxidative stress, thereby indicationg the protective effects of MSE in H 2 O 2-induced oxidative stress.