An image recording apparatus capable of correctly determining a color shift value between recording heads of different color. The image recording apparatus has each recording head print two types of patches as patterns on a conveyance belt and has a reflection intensity detection unit read reflection intensities of the two patches to determine the color shift value and correct the color shift value so as not to include a position shift value between a reference position and a position where the actual reading has started. The image recording apparatus for recording a pattern to a color image conveyance medium and reading the recorded pattern comprises a feeding unit that feeds the color image conveyance medium along a feeding path, a first image forming unit that records the pattern to the color image conveyance medium in a first color, a second image forming unit that records the pattern to the color image conveyance medium in a second color, a reflection intensity detection unit that reads a reflection intensity of the pattern, an image formation control unit for calculating from the reflection intensity a color shift value of the second image forming unit with respect to the first image forming unit, wherein the first image forming unit records a first pattern of a first interval and the second image forming unit records a second pattern of a second interval overlapping the first pattern so that a first patch having the first pattern and the second pattern overlapped is formed, and wherein the first image forming unit records a third pattern of the second interval and the second image forming unit records a fourth pattern of the first interval overlapping the third pattern so that a second patch having the first pattern and the second pattern overlapped is formed.