According to one embodiment, an X-ray diagnosis apparatus comprises a C-arm, a support mechanism rotatably supporting the C-arm, a rotation driving unit driving rotation of the C-shaped arm, an X-ray tube mounted on the C-arm, an X-ray detector mounted on the C-arm, a control unit controlling the X-ray tube and the X-ray detector, a storage unit storing two-dimensional images generated, a first reconstruction processing unit reconstructing first three-dimensional images respectively corresponding to a plurality of cardiac phases based on acquired two-dimensional images, a positional shift amount calculation unit calculating positional shift amounts respectively corresponding to cardiac phases based on the first three-dimensional images, and a second reconstruction processing unit reconstructing a single second three-dimensional image with a reduced positional shift based on the plurality of acquired two-dimensional images by using the calculated positional shift amounts.