Disclosed herein are a rail system and an X-ray imaging apparatus using the same. The rail system includes a rail unit, a detecting unit and an X-ray generating unit. The rail unit is provided on a support surface and extends for a predetermined length. The detecting unit is provided on the rail unit and includes a detector stand which is provided on the rail unit so as to be movable in the longitudinal direction of the rail unit, a detector arm which has a bent structure and is provided on a side surface of the detector stand so as to be movable upwards and downwards, and a detector which is rotatably coupled to the detector arm. The X-ray generating unit is provided on the rail unit at a position facing the detector and includes a tube stand which is provided on the rail unit so as to be movable in the longitudinal direction of the rail unit, a tube arm which is provided on the tube stand so as to be movable upwards and downwards, an X-ray tube which is coupled to the tube arm so as to be rotatable with respect to the tube arm, and a collimator which is fastened to the X-ray tube.