In the case where an image is formed with a mixture of large and small droplets by bi-directional printing in an ink jet printing apparatus in which ink is ejected in the form of, e.g., a droplet for printing operation while scanning by a print head, misalignment caused by a difference in ejection speed between the large and small droplets is prevented. For this purpose, there is provided a printing registration method according to the present invention comprises the steps of forming reference dots with the large and small droplets in forward scan printing, forming shifted dots in reverse scan printing on changed registration conditions, acquiring a adjustment value of the condition of dot forming positions on the basis of optical characteristics according to a plurality of shifting amounts of the relative printing positions between forward scanning and reverse scanning, controlling the order of formation of the large and small dots in the forward scanning and the reverse scanning, and correcting the adjustment value according to the offset amount of the small dot forming positions on the basis of the difference in ejection speed or the like.