A tandem-type image forming apparatus includes a toner mark pattern forming unit configured to form a toner mark pattern; a sensor configured to detect the toner mark pattern; a first determining unit configured to determine presence or absence of color misregistration based on the detected result; and a color misregistration correcting unit configured to correct the color misregistration based on the determined result. The toner mark pattern includes paired toner marks disposed at different coordinates in the sub-scanning direction. One of the paired toner marks has their ends at different coordinates in the main scanning direction with respect to those of the other one. The first determining unit determines the presence or absence of the color misregistration in the main scanning direction based on the result of the detection of the paired toner marks.