A printer gradation correcting method, comprises the steps of: outputting a color patch image by a printer based on image data of a color patch image; measuring a gradation of the outputted color patch image by a color measuring device so as to obtain a gradation measurement value; and correcting a gradation characteristic of the printer based on the gradation measurement value. The color patch image includes a patch-shaped image having a uniform gradation of a predetermined gradation representative value and gradation fluctuation of a predetermined color component added in the patch-shaped image, and the added gradation fluctuation is structured such that a total of gradation fluctuation measured in a measurement region by the color measuring device becomes a predetermined value. The gradation characteristic of the printer is corrected based on the gradation representative value, the predetermined value of the total of gradation fluctuation, and the gradation measurement value.