Provided is a cosmetic agent superior in a whitening effect (including prophylaxis and removal of pigmented spot) and having high safety. In addition, a superior melanin production suppressive agent is provided.A cosmetic agent or melanin production suppressive agent comprising (A) a cysteine derivative represented by the formula (I) or a salt thereof:whereinX and Y are each independently OR1 or NHR2 wherein R1 and R2 are each independently a hydrogen atom or a C1-22 alkyl group；Z is a hydrogen atom or a C1-22 alkyl group； andW is a C1-22 alkyl group, a C1-22 alkoxy group or a C1-22 alkylamino group,and(B) a whitening agent.
