PROBLEM TO BE SOLVED: To avoid X-ray photography of an unintended region caused by a change in a posture of a subject in an X-ray photography system.SOLUTION: An X-ray photography system comprises: an X-ray tube for applying X-rays; an X-ray detector for detecting the X-rays; an optical photography unit for performing optical photography of a subject, and generating action information of the subject; and an action determination unit for determining whether the subject is considered to be still or not on the basis of the action information.SELECTED DRAWING: Figure 2【課題】X線撮影システムにおいて、被検体の体勢の変化に起因する意図しない部位のX線撮影を回避すること。【解決手段】X線撮影システムは、X線を照射するX線管と、X線を検出するX線検出器と、被検体の光学撮影を行なって前記被検体の動作情報を生成する光学撮影部と、動作情報に基づいて被検体が不動とみなせるか否かを判断する動作判断部と、を有する。【選択図】 図2