One aspect of the present invention is to provide an image forming apparatus and a method to control the same, capable of shortening a time necessary for color alignment and correcting color position deviation of all printed matters by reflecting a position deviation between the colors in real time. According to one aspect of the present invention, the image forming apparatus in accordance to the present invention comprises: a plurality of photosensitive bodies disposed along a direction of progress of an intermediate transfer body and corresponding to a plurality of colors; an exposure unit to form an electrostatic latent image by irradiating light on the plurality of photosensitive bodies; a development unit to form toner images by supplying a toner to the plurality of photosensitive bodies; the intermediate transfer body to which the toner images formed on the plurality of photosensitive bodies are transferred; a first sensing unit disposed between a first photosensitive body and a second photosensitive body among the plurality of photosensitive bodies to detect the toner image transferred to the intermediate transfer body; a last sensing unit disposed after a last photosensitive body among the plurality of photosensitive bodies to detect the toner image transferred to the intermediate transfer body; and a control unit to calculate a fixed error of the remaining colors with respect to a first color corresponding to the first photosensitive body before a printing operation based on an output value of the last sensing unit, calculating a variable error during the printing operation based on the output value of the first sensing unit, and controlling an exposure time of at least one among the remaining colors by reflecting the fixed error and the variable error.