A pharmaceutical composition and a health food composition for preventing, treating and improving obesity, which include an extract complex of bamboo leaves and quince as an active ingredient, are disclosed. Because the extract complex has an excellent anti-obesity effect without causing any side effects, the extract complex can be effectively used in a pharmaceutical composition and health food for preventing, improving and treating obesity. Therefore, a novel therapeutic agent whose effect goes beyond conventional natural anti-obesity drugs and a novel therapy can be provided.
