Objective: This study was conducted to investigate the antioxidant activity and inhibitory effect on oxidative DNA damage of Nelumbinis Semen Extracts Methods: Nelumbins semen were extracted with hot-water and ethylacetate (EtOAC). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging assay and Fe2+ chelating assay were performed for antioxidative effect and oX-174 RF I DNA cleavage assay and intracellular DNA damage assay were used for inhibitory effect on intracellular DNA damage. Results: In DPPH, Hydroxyl radical scavenging activity and Fe2+ chelating activity of EtOAC extracts were 96.22%, 53.53%, 64.72%, while those of hot-water extracts were 20.86%, 10.72%, 29.74% at 200㎍/㎖, respectively. In oX-174 RF I plasmid DNA cleavage assay, the protective effects of EtOAC and hot-water extracts against oxidative DNA damage were 76% and 6% at 200㎍/㎖, respectively. Conclusion: These results indicated that the seed extracts of Nelumbo nucifera can be used as a natural antioxidants, which effectively inhibits the oxidative DNA damage.