An X-ray image processing apparatus and method for processing X-ray images for generating a continuous X-ray image of relatively uniform converted gradations by pasting a plurality of consecutive divisional X-ray images. The plurality of consecutive divisional X-ray images are obtained along an examining body. Each of the consecutive divisional X-ray images is overlapped at its edge with an adjoining image. An index value for the respective divisional X-ray images is calculated based on pixel values in the overlapped portion between the images. Each of pixel values for the respective plurality of consecutive divisional X-ray images is adjusted or corrected so as to be relatively uniform to an index value for an adjoining divisional image. The gradation corrected divisional images are pasted together in order to produce the continuous image.