Provided are a plant extract composition and a pharmaceutical composition for inhibiting tyrosinase activity, preventing melanogenesis or treating melanogenesis, wherein the plant extract composition contains curcumin and resveratrol by weight ratio from 4:1 to 1:4. The plant extract composition and the pharmaceutical composition are useful for preventing and treating pigmentation for skin whitening, and achieve the effect of whitening skin and reducing pigmentation for a subject in topical site.
