Skin color is primarily determined by the amount of melanin pigmentation in the skin. In recent years, cosmetic compositions have been developed to reduce the melanin pigmentation in the skin. Treatment of the skin with whitening agents, from the pharmacological and cosmetological views, should provide safety and efficacy without side effects. Currently used whitening agents which are mostly cause many harmful and cytotoxic effects. In view of the lack of safe whitening agents, this study has been conducted to find the stable and harmless compounds inhibiting melanogenesis. The use of light and Herbal extract for the purpose of skin whitening has been formally reported. So, this study is to investigate the effects of LED irradiation and Bletillae rhizoma (Br) extract on tyrosinase activity and melanin biosynthesis in B16F0 melanoma cells. Melanin biosynthesis was induced by α-MSH. Experimental group were conducted five groups; 1) Pre-LED group (LED light irradiation, followed by 1 μM α-MSH) 2) Post-LED group (α-MSH treat, followed by LED light irradiation) 3) Pre-Br extract group (Br extract treat, followed by 1 μM α-MSH) 4) Post-Br extract group (α-MSH treat, followed by 10 μg/ml Br extract) 5) LED and Br extract group. The melanin contents, tyrosinase activity, dendrite length ...