This study was performed to evaluate the effect of persimmon leaves extract on the reactive oxygen species (ROS) in cultured melanoma cells. The B16/F10 melanoma cells were treated with various concentrations of t-butyl hydroperoxide (t-BHP). And also, the effect of persimmon leaves (PL) extract on the cytotoxicity mediated by t-BHP was done on the cell viability, tyrosinase activity and melanogenesis by colorimetric assays. In this study, t-BHP decreased cell viability in dose-dependent manner and XTT90 and XTT50 values were measured at 10 and 35 uM of PL, respectively in these culture. And also, XTT50 value was assessed as a highly toxic effect on cultured melanoma cells by the toxic criteria. In the effect of PL extract on the t-BHP-mediated cytotoxicity, PL extract significantly increased the cell viability injured by t-BHP in cultured B16/F10 melanoma cells. PL also showed the decreased tyrosinase activity and melanogenesis. From these results, it is suggested that ROS such as t-BHP showed highly toxic effect on cultured melanoma cells, and also, PL extract inhibited the tyrosinase activity and melanogenesis in cultured melanoma cells injured by ROS.