PROBLEM TO BE SOLVED: To provide a method of finding a whitening agent having a new action mechanism which is difficult only by paying attention to whitening effects based on the existing action mechanism, specifically a whitening agent having cell adhesion inhibitory action of keratinocyte.SOLUTION: Provided is a whitening agent having a new action mechanism by pay attention to cell adhesion inhibitory action of keratinocyte comparing integrin production inhibitory action of keratinocyte, adhesion inhibitory action on a basement membrane of keratinocyte, and upper layer movement promoting action of keratinocyte assessing cell adhesion inhibitory action of keratinocyte and selecting a whitening agent with the action as an index.
