To provide an arginase activity promoter higher in arginase activity-promoting effect than conventional ones, and to provide a skin care preparation having high moisturization-sustaining effect and rough skin-ameliorative effect.

The arginase activity promoter comprises apricot juice as active ingredient. The skin care preparation comprises 0.0001-5 wt.% of the arginase activity promoter in terms of apricot juice dry residues and 0.001-10 wt.% of one or more compounds selected from L-aspartic acid, L-glutamic acid and their salts.