Disclosed are an X-ray irradiating device having a function of selecting an automatic radiographic mode and an X-ray imaging method using the same. The X-ray irradiating device includes an X-ray source, a motion sensor configured to detect an X-ray source pointing direction, and a controller configured to select any one of a plurality of radiographic modes according to a pointing angle signal received from the motion sensor. The X-ray imaging method, which uses the above described X-ray imaging apparatus, includes setting a reference plane as a reference value for a pointing angle in which an X-ray source is directed, detecting the pointing angle relative to the reference plane by using a motion sensor and selecting a radiographic mode corresponding to the detected pointing angle, and performing a radiography by controlling the X-ray source with a set value corresponding to the selected radiographic mode.
