According to one embodiment, an X-ray diagnosis apparatus includes an X-ray tube, an X-ray detector, an operating unit, and processing circuitry. The processing circuitry determines a focal-spot size of X-rays in second moving picture imaging after first moving picture imaging, based on an output of the X-ray detector in the first moving picture imaging, and determines a focal-spot size of X-rays in third moving picture imaging after the second moving picture imaging, based on an output of the X-ray detector in the second moving picture imaging.