Provided is a plant extract composition and a pharmaceutical composition thereof for reducing body weight and body fat, wherein the plant extract composition comprises a green tea extract and a turmeric extract respectively 30 wt % to 75 wt % and 20 wt % to 55 wt % of a total weight of the composition. In diet-induced obesity models, either obesity is induced first or simultaneously with administration, the plant extract composition and a pharmaceutical composition thereof can reduce body weight and body fat more significantly than a single plant extract or commercially available weight loss drugs.