Disclosed is to provide a composition for skin-whitening or preventing or improving skin wrinkles, comprising a green tea extract which has modified amounts of ingredients. More specifically, the extract and composition according to one aspect of the present disclosure are derived from natural plants that cause less irritation to the skin and are eco-friendly, thus they are safe, and thereby the extract and composition can exhibit excellent effects of effectively inhibiting melanin production and tyrosinase activity and preventing or improving skin whitening, and can exhibit excellent effects of effectively inhibiting the expression of MMP-1 and preventing or improving skin wrinkles.