A good positioning technique is essential for obtaining accurate diagnostic information in radiography. In this study, we developed the imaging techniques which produced the X-ray plane image using CT images in order to confirm the positioning of the phantom under the X-ray equipment. First, we scanned the skull phantom by CT (Computed tomography) and obtained CT images. Next, we measure the positioning information of the phantom under the X-ray equipment by using scene analysis. And we produced an X-ray plane image from CT image data corresponding to the detected phantom position under the X-ray equipment using image processing techniques. As the result, we could obtain the X-ray plane image having the same image quality as the X-ray film image. By using proposed techniques, we can confirm the X-ray image without exposure of X-rays and perform the positioning practice efficiently. It is expected that our techniques are useful for leaning positioning technique in various organs.