A color image forming apparatus includes a plurality of mark sensing devices are arranged between a plurality of photoconductors arranged on an intermediate transfer belt to sense a mark transferred to a region of the intermediate transfer belt corresponding to an interval between successive recording media. As an exposure time to form an electrostatic latent image on a photoconductor, on which a following developer image will be formed, is determined, minimized mis-registration and consequently, improved color registration correction efficiency are accomplished. Also, automatic color registration correction is performed on per printing operation basis, resulting in improvement in image quality.