The present invention relates to body shape-correcting trousers, and more particularly, to body shape-correcting trousers in which parts of the trousers have different densities to generate forces for externally rotating a wearer's legs around the pelvis and to thus correct bowed legs or "O"-shaped legs. The present invention enables bowed legs or O-shaped legs of the wearer to be corrected curing everyday life and enables the leg joints of the wearer to be kept in a correct posture, thereby preventing arthritis or aging cartilage.