The X-ray imaging apparatus includes an X-ray generator to generate X-rays having at least two different energy levels and irradiate the X-rays onto a subject, a detector to detect the X-rays irradiated by the X-ray generator and transmitted through the subject, and a device to obtain images from the X-rays detected by the detector, to obtain bone image information and soft tissue image information of the subject, based on the obtained X-ray images, and to produce one image including the bone image information and the soft tissue image information.