An image forming apparatus includes an image forming unit adapted to form images of a plurality of colors in a manner in which a predetermined pattern of a predetermined color is registered thereon and superimpose those images to form a color image, a controller configured to control the image forming unit so as to form a patch image of each color for density detection, and a detector configured to detect the density of each of the patch images. The controller controls the image forming unit so as to superimpose the predetermined pattern of the predetermined color upon the patch image of a predetermined color and not to superimpose the predetermined pattern of the predetermined color upon the patch images of the other colors.