This invention relates to a layout structure of a mutual-compensated MOS image sensor including a base, multiple light sensing elements, multiple transistors and multiple colorful optical filtering films, in which, the base includes a pixel array region composed of multiple pixels, each pixel includes a light sensing region and an active element region, and the pixels are isolated by the isolation regions and the light sensing regions have different sizes, besides, multiple light sensing elements are defined in the light sensing regions, multiple transistors are matched in the active regions, multiple colorful filtering films are matched above the corresponding pixels to form a color filter array. |