An X-ray imaging system takes an X-ray of an examined part of an examination subject supported by a bed. The X-ray imaging system includes: an X-ray generator that is an X-ray source; an X-ray image pickup apparatus arranged to be opposed to the X-ray generator and configured to take an X-ray having been radiated from the X-ray generator to the examination subject and passed through the examination subject; a seven-axis vertical multi-joint first robot supporting the X-ray generator; a seven-axis vertical multi-joint second robot supporting the X-ray image pickup apparatus; and a robot controller configured to control operations of the first robot and the second robot such that the X-ray generator and the X-ray image pickup apparatus move on a spherical shell centering around an isocenter C while causing the isocenter C and the examined part to substantially coincide with each other.