Disclosed is a toner cartridge, which comprises a case, a toner outlet and a gate that can slide to close the toner outlet. The inside of the gate has a bump which can be resisted by the opening mechanism to open the toner outlet. The outside of the gate has an elastic buckle which can be resisted by the closing mechanism to close the toner outlet. The outside of the toner feeding compartment has a notch; the bottom surface of the notch is connected with the outside of the toner feeding compartment through the guiding slope. When the gate is in the closing position, the elastic buckle and the notch coordinate; when the gate is in the opening position the elastic buckle separates from the notch and puts over the outside of the toner feeding compartment.