The present invention relates to using supercritical a CO2-extracted product of Alpinia Oxyphylla Miq. for melanin inhibition and melanoma treatment. Medical and cosmetic purposes of using supercritical a CO2-extracted product of Alpinia Oxyphylla Miq. for melanogenesis inhibition and melanoma treatment are provided. Accordingly, the moving ability of human melanoma cells can be effectively reduced.本發明揭示益智仁之一經超臨界CO2萃取的產物可被用來抑制黑色素生成以及治療黑色素瘤。