According to one embodiment, an X-ray computed tomography apparatus comprises an X-ray generating unit, an X-ray detecting unit, a rotating mechanism configured to rotate the X-ray generating unit and the X-ray detecting unit, a reconstruction processing unit configured to reconstruct first images respectively corresponding to volumes, a shift detecting unit configured to detect shifts of an object image due to warp of the top within a reconstruction coordinate system of the reconstruction processing unit, which shifts respectively correspond to the first images, and a control unit configured to move an origin of the reconstruction coordinate system for each of the volumes based on each of the detected shifts and control the reconstruction processing unit to reconstruct second images, which shifts respectively correspond to the volumes from the output from the X-ray detecting unit on the reconstruction coordinate system whose origin has been moved.