Sophora japonica has been used for treatment of liver and blood-related diseases in herbology. We evaluated whitening activities of Sophorae Flos and Fructus. Sophorae Flos and Fructus were extracted with methanol (MeOH) and divided into petroleum ether, ethyl acetate(EtOAC) and water fraction. For whitening effect by western blot in B16 F10 cells, we analyzed it by investigating the effect of tyrosinase, TRP-l (tyrosinase-related protein 1), TRP-2 (tyrosinase-related protein 2) and MITF (microphthalmia-associated transcription factor) protein expression. The protein expressions of tyrosinase, TRP-1, TRP-2 and MITF in B16 F10 cells treated with Sophorae Flos and Fructus extract were reduced in a dose-dependant manner. Therefore, these results suggest that Sophorae Flos and Fructus have useful plant resource to be developed as functional cosmetic.