An X-ray detector and an X-ray image system using the same are disclosed. The X-ray image system comprises an X-ray generator irradiating X-rays to an object to be photographed; an X-ray detector including a first photoelectric converter receiving X-rays transmitted the object and converting the X-rays in to a first electric signal and a second photoelectric converter converting the X-rays in to a second electric signal; a first image processor processing a first image of the object on the basis of the first electric signal of the X-ray detector; a second image processor processing a second image of the object on the basis of the second electric signal of the X-ray detector; a display module displaying the first and second processed images of the object; and a controller controlling the X-ray generator, the X-ray detector, the first and second image processors and the display module.