PURPOSE: To obtain a new peptide having a tyrosinase activity inhibiting action and suitable for the application to the use requiring the inhibiting action.

CONSTITUTION: This peptide or its salt has the amino acid sequence shown by the following general formula. Ala-Val-Thr-Asp-Asn-Glu-Ile-Val-Pro-Gln-Cys- Leu-Ala-Asn-Gly-Ser-Lys-Cys-Tyr-Ser-His-Asp-Val-Cys-Cys-Thr-Lys-Arg-Cys-His- Asn-X-Ala-Lys-Lys-Cys-Val-Thr (X is DOPA or Tyr). As an alternative, a peptide or its salt obtained by removing 10 amino acids from the N-terminal of the above peptide and deficient in one or more constituent amino acids is used. These peptides or their salts are useful as tyrosinase activity inhibiting agents.