PURPOSE: A composition containing a Momordica charantia L. extract for promoting collagen synthesis is provided to prevent and treat striae distensae and to be used as a cosmetic product or an external use formulation. CONSTITUTION: A cosmetic composition for preventing or treating striae distensae contains 0.000001-90.0 wt% of a Momordica charantia L. extract as an active ingredient. The cosmetic composition is lotion, gel, water soluble liquid, cream, essence, an oil-in-water type or water-in-oil type basic skin care formulation, oil-in-water type or water-in-oil type make-up base, foundation, skin cover, lip stick, lip gross, face powder, eye shadow, cheek color, or eyebrow pencil. An external use composition for preventing or treating striae distensae contains the extract as an active ingredient. 본 발명은 여주추출물을 포함하는 팽창선조 예방 또는 개선용 조성물에 관한 것으로, 우수한 콜라겐 합성 촉진, 피부 보습, 팽창선조 예방 및 개선 효과를 보이기 때문에, 튼살(팽창선조)의 예방 및 개선 용도로서 화장품 또는 외용제로 사용될 수 있다.