A technique that can stably realize highly accurate image adjustment processing regardless of deterioration in an image forming characteristic and the like is provided. An image forming apparatus that forms, on an image formation medium, a gradation pattern formed as an image of density changing according to a gradation step, and performs predetermined image adjustment processing on the basis of a print state of the gradation pattern formed on the image formation medium, the image forming apparatus comprising a fluctuation-information acquiring unit configured to acquire information on a degree of fluctuation in a predetermined characteristic affecting an image quality of an output image; and a control unit configured to form, on the image formation medium, a gradation pattern in which a density changing amount is changed according to the gradation step on the basis of the information acquired by the fluctuation-information acquiring unit.