Quercetin (3, 3', 4', 5, 7-pentahydroxylflavone) is one of the representative flavonoids and is present in many vegetables and fruits. We studied the effects of quercetin on melanin production in hair follicle tissues from the buccal region of C3H/HeN Jel mice. These follicle tissues synthesized larger amounts of melanin than control tissue, with the amount dependent on the concentration of added quercetin. Additionally, the expression of tyrosinase protein was significantly enhanced in proportion to increases in the concentration of quercetin added. Nevertheless tyrosinase mRNA expression was not changed. In addition, tyrosinase-related protein-2 (TRP-2), which is a melanogenic enzyme, was increased depending on the concentration of added quercetin but its mRNA expression was not altered. These results show that quercetin stimulates the synthesis of tyrosinase protein as well as TRP-2 protein, thereby enhancing melanin producibility in hair follicle tissues from the buccal region of C3H/HeN Jel mice.