Abstract: An undergarment having body contouring function being made from stretchable material and having stitching or seams located at the front and rear side of the undergarment. The fat of the body of the wearer is pushed toward the breast or hip such that the breast and the hip of the wearer look stiffer and larger. A zipper is provided at one lateral side of the undergarment for easy wearing of the undergarment. The bottom end of the groin is provided with two crotch linings such that when the wearer closes the two legs together, an opening will not occur and when the two legs are separated apart, an opening is formed for enabling the wearer to use toilet facilities easily without having to remove the undergarment.