PROBLEM TO BE SOLVED: To provide a skin whitening agent, a melanogenesis inhibitor and a dopa oxidase activity inhibitor, which have high safety.SOLUTION: A dopa oxidase activity inhibitor includes a compound represented by formula (I) or its salt as an active constituent.COPYRIGHT: (C)2013,JPO&INPIT【課題】安全性が高い、美白剤、メラニン生成抑制剤及びドーパオキシダーゼ活性抑制剤の提供。【解決手段】下記式(I)で示される化合物又はその塩を有効成分とするドーパオキシダーゼ活性抑制剤。【選択図】なし