PURPOSE: To obtain an additive for preparing a beauty product, comprising a new oligopeptide and capable of manifesting excellent skin beautifying and humectant effects and improving the skin conditions.

CONSTITUTION: This additive for preparing a beauty product is obtained by using an oligopeptide having an amino acid sequence of formula I or II [A, X and I are amino acids selected from glycine, hydroxyproline, proline, arginine, lysine, hydroxylysine and histidine; Y is the amino acid sequence such as A, X, I, A-X, X-I or A-I) or its acid addition salt or metallic complex. An oligopeptide having a sequence in natural collagen, elastin, keratin, fibronectin or connective tissue protein is especially preferred as the oligopeptide used herein. Among them, the especially utilized oligopeptide is mainly the glycine, proline and/or hydroxyproline. The oligopeptide is important due to action thereof on the depth of the skin.