This study was to investigate the effect of Ponciri Fructus ethanol extract on the melanogenesis. The Ponciri Fructus markedly decreased melanin contents of B16F10 cells at a dose of $80{mu}g/m{ell}$. It was observed that the color of cell pellets was totally whitened compared with the control. The treatment of Ponciri Fructus inhibited tyrosinase activity, regulate melanin biosynthesis as the key enzyme in melanogenesis. Regarding protein levels of the melanogenic enzymes, the Ponciri Fructus dose-dependently decreased tyrosinase and TRP-1 protein levels, and tyrosinase and TRP-1 were detected in similar manner. These results suggest that the Ponciri Fructus ethanol extract exerts its depigmenting effects through the suppression of tyrosinase and TRP-1.