Organic solvent (methanol, ethanol, and acetone) extracts and water extracts of cherry (Prunus serrulata var. spontanea) blossoms were prepared, and antioxidant activities of the extracts were evaluated. Methanolic CBE (100 microg/ml) showed the highest total phenol content (104.30 microM), radical scavenging activity (34.2%), and reducing power (0.391). The effect of CBE on DNA damage induced by H(2)O(2) in human leukocytes was evaluated by Comet assay. All CBE was a potent dose dependent inhibitor of DNA damage induced by 200 microM of H(2)O(2), methanolic CBE showed the most strong inhibition activity. The methanolic CBE of 500 microg/ml showed 38.8% inhibition against growth of human colon cancer cell line HT-29. These results indicated that cherry blossoms could provide valuable bioactive materials.