Resveratrol exhibited the inhibitory activity against mushroom tyrosinase (EC1.14.18.1) through a kcat inhibition. Resveratrol itself did not inhibit tyrosinase but rather was oxidized by tyrosinase. In the enzymatic assays, resveratrol did not inhibit the diphenolase activity of tyrosinase when l-3,4-dihydroxyphenylalanin (l-DOPA) was used as a substrate; however, l-tyrosine oxidation by tyrosinase was suppressed in presence of 100μM resveratrol. Oxidation of resveratrol and inhibition of l-tyrosine oxidation suggested the inhibitory effects of metabolites of resveratrol on tyrosinase. After the 30min of preincubation of tyrosinase and resveratrol, both monophenolase and diphenolase activities of tyrosinase were significantly suppressed. This preincubational effect was reduced with the addition of l-cysteine, which indicated kcat inhibition or suicide inhibition of resveratrol. Furthermore, investigation was extended to the cellular experiments by using B16-F10 murine melanoma cells. Cellular melanin production was significantly suppressed by resveratrol without any cytotoxicity up to 200μM. trans-Pinosylvin, cis-pinosylvin, dihydropinosylvin were also tested for a comparison. These results suggest that possible usage of resveratrol as a tyrosinase inhibitor and a melanogenesis inhibitor.