An X-ray CT system comprises: an X-ray generator that generates two cone beam X-radiations which pass through two successive slabs; an X-ray detector that detects a two-dimensional distribution of intensities exhibited by the two cone beam X-radiations having passed through the two slabs; an acquisition unit that acquires a plurality of view of projection data representing the two slabs on the basis of detection signals sent from the X-ray detector; and a reconstruction unit that reconstructs an image according to the projection data.