Cosmetic compositions comprising crude saponins of Gynostemma pentaphyllum are provided to inhibit activity of tyrosinase without side effects or toxicity and improve stability in cosmetics, so that the composition is useful for whitening the skin. A cosmetic composition for whitening the skin comprises 0.1-1.0 wt.% of the extract of Gynostemma pentaphyllum which is prepared by extracting leaf and vine of Gynostemma pentaphyllum in ethanol with ultrasonic wave for 4 hours, or 0.01 to 1.0 wt.% of crude saponins of Gynostemma pentaphyllum which are prepared by fractionating the ethanol extract of Gynostemma pentaphyllum with hexane and butanol, sequentially.본 발명은 멜라닌 합성 저해 효과가 매우 우수한 돌외 조사포닌을 유효성분으로 함유하는 미백화장료 조성물에 관한 것이다.
