To provide a method for enabling a search for a skin sagging improving agent using the phenomenon involved in the development of sagging in the vicinity of a skin surface layer in which the action of the skin external preparation is likely to be exhibited and a skin sagging improving agent with excellent effect.SOLUTION: The method includes a step in which at least one of a morphological changes of epidermal keratinocytes due to a load of gravity artificially applied to the epidermal keratinocytes and change in a state of change in the cellular shape change control substance of epidermal keratinocytes is indexed by the epidermal keratinocytes； and a step for effectively improving sagging of the skin by using a slackening agent and a cumisctin extract.SELECTED DRAWING: Figure 3【課題】皮膚外用剤の作用が発揮されやすい皮膚表層近傍におけるたるみ発生に関与する現象を指標とした皮膚たるみ改善剤の探索を可能にする方法及びその効果に優れた皮膚たるみ改善剤を提供する。【解決手段】表皮ケラチノサイトに人為的に重力を負荷し、該負荷に起因する表皮ケラチノサイトの形状変化、表皮ケラチノサイトの細胞形状変化制御物質の状態変化、のうち、少なくとも一つ以上を指標とする工程。たるみ改善剤、又、クミスクチン抽出物を用いることにより、皮膚のたるみを効果的に改善する工程を含む。【選択図】図３
