A composition for preventing or ameliorating obesity, comprising an extract of Yangchus sand as an active ingredient, characterized in that the extract of Yangshun sand is extracted with water, and 100 mg/kg to 500 mg/kg based on oral administration to mice is included. The present invention relates to a composition for preventing or improving obesity. The present invention provides an extract of Yangchusang having an anti-obesity effect by inhibiting the increase in adipocytes in the liver, limiting the size of adipocytes, inhibiting the production of triglycerides, and inhibiting the expression of mRNA in vivo. The present invention provides a composition for preventing or improving obesity. [Selection diagram] Fig. 3陽春砂抽出物を有効成分として含有する肥満予防又は改善組成物に関し、前記陽春砂抽出物を水で抽出することを特徴とし、マウスの経口投与を基準にして１００ｍｇ／ｋｇ～５００ｍｇ／ｋｇ含まれていることを特徴とする肥満予防又は改善組成物に関する。本発明は、陽春砂抽出物の肝内脂肪細胞増加の抑制、脂肪細胞の大きさの制限、中性脂肪生成の抑制、ｉｎ ｖｉｖｏでのｍＲＮＡ発現の抑制を通じて抗肥満効能を有する陽春砂抽出物を含有した肥満予防又は改善組成物を提供する。【選択図】図３
