An image forming apparatus for forming an image on a transfer sheet based on image data, comprises an operating section to determine a setup about a margin region on which an image is not formed at an edge portion of the transfer sheet, a control section to determine an inner region having a specified width and being adjacent to the determined margin region as a density change region in which an image density is changed, and determines a more inner region located inward more from the density change region as a regular density region in which an image is formed with a regular image density, and an image forming section to form an image in the density change region based on image data on the condition where the image density is reduced and to form an image in the regular density region based on image data without changing the image density.