An ink jet recording apparatus is operated under a basic recording mode for recording through use of a basic unit pixel which is associated with a unit recording area corresponding to a unit print cycle, and a high-resolution recording mode for recording through use of a fine unit pixel, a plurality of fine unit pixels being arranged within the unit recording area in a main scanning direction of the recording head. The print data is developed into the jetting data such that each bit therein indicates whether the recording is conducted or not in each associated fine unit pixel, when the high-resolution recording mode is selected.