Disclosed are an X-ray computed tomographic imaging apparatus and a method for same. The X-ray computed tomographic imaging apparatus of the present invention comprises: a tomograph which radiates light onto an object being imaged by tomography, and detects the light passing through the object being imaged by tomography a magnification rate determining unit which determines the magnification rate of an image of the object being imaged by tomography using the hardware property of the tomograph and/or the size of an input voxel and a magnification rate controller which moves the tomography in accordance with the determined magnification rate, thereby obtaining images having a high resolution.