An image forming apparatus includes a main body, a development cartridge supplying toner accommodated in a toner accommodating portion to an electrostatic latent image formed on a photoconductor to form a toner image, a toner refilling portion in the development cartridge and on which a toner refill cartridge for refilling toner in the toner accommodating portion is mounted, and a controller controlling operations of the image forming apparatus based on a connection between the development cartridge mounted on the main body and the toner refill cartridge mounted on the toner refilling portion. The toner refilling portion connects the toner refill cartridge to the main body through an interface between the development cartridge and the main body.