PURPOSE: A cosmetic composition is provided to be harmless to humans and have an excellent pruritus relief effect, thereby having an excellent atopic dermatitis improvement effect and skin whitening effect and being usefully used for cosmetic production. CONSTITUTION: A cosmetic composition for skin whitening includes palmitoyl-Lys-Thr-Thr-Lys-Ser as an active ingredient. A content of the palmitoyl-Lys-Thr-Thr-Lys-Ser is 0.00001-1.0 weight% about the total weight of the composition based on a dry weight. Peptide derivative palmitoyl Lys-Thr-Thr-Lys-Ser has an excellent protease-activated receptor 2 (PAR-2) inhibition effect which inhibits an increasing effect of an intracellular calcium concentration by trypsin when the peptide derivative palmitoyl Lys-Thr-Thr-Lys-Ser is treated in HaCaT cells with the trypsin.본 발명은 피부 가려움증 개선용 및/또는 피부 미백용 화장료 조성물에 관한 것으로서, 보다 상세하게, 상기 화장료 조성물은 PAR-2활성 저해효과를 갖는 펩타이드 유도체 (팔미토일-Lys-Thr-Thr-Lys-Ser)를 유효성분으로 함유하여 우수한 피부 가려움증 개선 및 이로 인한 아토피 피부염 개선 효과 및/또는 피부 미백 효과를 갖는 것을 특징으로 한다.
