There is provided a multiimage forming apparatus for forming image data onto photo sensitive drums by an electrophotographic system. This apparatus comprises: an image forming circuit to form different images onto the photo sensitive drums; a transfer device to transfer the images on the drums onto the same transfer paper; a conveying belt to convey the transfer paper; a control circuit to control the image forming circuit so as to form registration marks to match the positions of the images onto the drums; CCD detectors to detect the recording positions of the marks; and a correcting circuit to correct at least two of the positional direction in the conveying direction of the belt, the positional deviation in the direction perpendicular to the belt conveying direction, the magnification of the image, and the inclination of the image on the basis of the detection outputs of the detectors. With this apparatus, the positional deviations of the images which occur during the image formation can be accurately corrected, so that the images can be accurately formed on the transfer paper by reading and matching the position matching registration marks.