1. An X-ray CT apparatus for executing a CT for local region of an object to be examined in which a support means having an X-ray generator and an X-ray detector faced to each other is relatively rotated around the object disposed between said X-ray generator and said X-ray detector, said apparatus comprising: an image data input means for taking in an X-ray image data of said object together with attribute information thereon, said X-ray image data of said object being obtained by an X-ray detector of another X-ray apparatus; a display operation means for displaying said X-ray image data thereon as a scout view for examination and receiving operation of designating an interested area on the displayed X-ray image; and a position control means for relatively moving said object, to said X-ray generator and said X-ray detector, in order to execute a CT for local region of said interested area, based on said operation of designating the interested area and said attribute information.