An X-ray imaging apparatus comprising: an X-ray generating unit configured to generate X-rays and irradiate an object with the X-rays; an X-ray detector configured to detect X-rays irradiated from the X-ray generating unit and transmitted through the object; and a host device configured to generate and display a plurality of X-ray images from the detected X-rays and to display an image containing at least one of bone image information and soft tissue image information of the displayed X-ray images, the bone image information and soft tissue image information corresponding to at least one region selected by a user; wherein the X-ray detector is further configured to detect first energy X-rays and second energy X-rays, wherein the first energy X-rays and the second energy X-rays have different energy levels, and wherein the host device comprises an X-ray image generating unit configured to generate a first energy X-ray image from the first energy X-rays detected by the X-ray detector and to generate a second energy X-ray image from the second energy X-rays detected by the X-ray detector; an image display unit configured to display at least one of the first energy X-ray image and second energy X-ray image generated by the X-ray image generating unit; an input unit configured to receive, from the user, selection of at least one region of the image displayed on the image display unit; and an image information extraction unit configured only to extract separate bone image information or soft tissue image information from the first energy X-ray image and the second energy X-ray image for the at least one region selected by the user, wherein the image display unit is further configured to display a bone image or soft tissue image corresponding to the at least one region selected by the user, and wherein the bone image contains the bone image information extracted by the image information extraction unit and the soft tissue image contains the soft tissue image information extracted by the image information extraction unit. an X-ray generating unit configured to generate X-rays and irradiate an object with the X-rays; an X-ray detector configured to detect X-rays irradiated from the X-ray generating unit and transmitted through the object; and a host device configured to generate and display a plurality of X-ray images from the detected X-rays and to display an image containing at least one of bone image information and soft tissue image information of the displayed X-ray images, the bone image information and soft tissue image information corresponding to at least one region selected by a user; wherein the X-ray detector is further configured to detect first energy X-rays and second energy X-rays, wherein the first energy X-rays and the second energy X-rays have different energy levels, and wherein the host device comprises an X-ray image generating unit configured to generate a first energy X-ray image from the first energy X-rays detected by the X-ray detector and to generate a second energy X-ray image from the second energy X-rays detected by the X-ray detector; an image display unit configured to display at least one of the first energy X-ray image and second energy X-ray image generated by the X-ray image generating unit; an input unit configured to receive, from the user, selection of at least one region of the image displayed on the image display unit; and an image information extraction unit configured only to extract separate bone image information or soft tissue image information from the first energy X-ray image and the second energy X-ray image for the at least one region selected by the user, wherein the image display unit is further configured to display a bone image or soft tissue image corresponding to the at least one region selected by the user, and wherein the bone image contains the bone image information extracted by the image information extraction unit and the soft tissue image contains the soft tissue image information extracted by the image information extraction unit.