1. An X-ray imaging apparatus comprising: an X-ray tube which radiates X-rays toward a subject; an X-ray detector which detects X-rays which propagate through the subject; an imaging unit which generates an image of the subject; a recognizer which recognizes a part to be subjected to X-ray imaging from the generated image of the subject; and a position controller which controls a respective movement of each of the X-ray tube and the X-ray detector to a respective position which corresponds to the part to be subjected to X-ray imaging, wherein the recognizer comprises a marker recognizer which recognizes a marker from the generated image of the subject in order to recognize the part to be subjected to X-ray imaging of the subject, and the marker is located at a target position of the subject.