The unique biochemical pathways in melanocytes responsible for melanogenesis provide us with a rational mechanism-based means for developing both pharmacological regulators of pigmentation and cytotoxic chemotherapeutic drugs for melanoma, Myricetin is a polyphenolic antioxidant and a component from Biotae Semen, Biotae orientalis Folium. Therefore, the present study was conducted to evaluate the effects of myricetin on the melanogenesis in human melanoma (HM₃KO) cells. The cells were treated for 5 days with myricetin at several concentrations (10 - 100 μg/ml). Treatment with myricetin dose-dependently suppressed cell growth in HM₃KO cells, But melanin formation was markedly increased by myricetin as a dose dependent manner. Myricetin did not affect to tyrosinase activity, which is a key enzyme for melanogenesis, but significantly increased the level of tyrosinase protein expression, These results suggest that myricetin stimulate melanin synthesis of human melanoma cells through the modification of tyrosinase protein expression.