PROBLEM TO BE SOLVED: To provide melanogenesis inhibitors and skin-whitening cosmetics.SOLUTION: The present invention relates to a melanogenesis inhibitor and a skin-whitening cosmetic comprising dihydroactinidiolide as an active ingredient, represented by the chemical formula (I).COPYRIGHT: (C)2015,JPO&INPIT【課題】メラニン産生抑制剤ならびに美白化粧料を提供する。【解決手段】化学式(I)で表される、ジヒドロアクチニジオリドを有効成分として含有するメラニン産生抑制剤および美白化粧料。【選択図】図1