An ink jet printing apparatus comprises a distributing unit configured to distribute print data for printing dot into data used for printing by first printing elements provided in a print head and data used for printing by second printing elements provided in the same print head, and a determining unit configured to, for the data used for printing by the respective parts of the printing element arrays of each of first and second print heads which have the overlapped print regions, determine a ratio between amount of the data used for printing by a combination of the first and second printing element arrays in the first print head and a combination of the first and second printing element arrays in the second print head.