The important role of melanin is skin protection against UV radiation from sunlight which induces DNA damage and skin cancer. The purposes of this study were to determine the effects of xanthoxylin on melanin content by measure melanin content at 405 nm, mRNA expression of regulatory melanogenesis proteins by RT-PCR and dendriticity in mouse B16F10 melanoma cells by photograph the pictures under microscope. This study found that xanthoxylin increased melanin content and mRNA expression of regulatory melanogenesis proteins (tyrosinase and Mitf). In addition, xanthoxylin also increased dendrites of mouse B16F10 melanoma cells and no effect on viability of mouse B16F10 melanoma cells. It could be concluded that xanthoxylin induced melanogenesis, increased dendrites and activated tyrosinase and Mitf expressions in mouse B16F10 melanoma cells.