An object of the invention is to provide a substance that activates saccharide uptake in epidermal cells and is thus expected to be effective in promoting skin cell neogenesis and metabolism. The invention provides a promoter for saccharide uptake in epidermal keratinocytes which comprises a purine base or a salt thereof as an active ingredient. The present invention further provides a method of promoting saccharide uptake in epidermal keratinocytes, comprising applying a purine base or a salt thereof to the skin.