An image forming apparatus includes an image carrying belt for carrying a toner image; an image forming station for forming toner image on the image carrying belt; a sheet feeding belt for feeding a sheet; a transfer member for transferring the toner image from the carrying belt onto the sheet fed on the feeding belt; and a controller for controlling speeds of the carrying belt and the feeding belt. The controller is capable of controlling a relative speed between the carrying belt and the feeding belt at multiple levels. The image forming station forms a first toner pattern on the carrying belt in a state that the relative speed is at a first level, and forms a second toner pattern on the carrying belt in a state that the relative speed is at a second level which is different from the first level. The transfer member transfers the first toner pattern and the second toner pattern onto the sheet carried on the feeding belt.