A transmitting assembly of a toner cartridge is provided. The transmitting assembly comprises a gear member, a tubular member disposed at the gear member and having an axial hole, an axial member provided with a shaft portion inserting into the axial hole and a head portion, an elastic member applying force on the axial member away from the gear member, two engaging claws provided with body portions disposed at the head portion and claw portions located at the body portions, and a torsional member connected with the engaging claws and applying force turning the engaging claws outward. The claw portions are located at two sides of the axial member, and abutting ends of the body potions are located at a center of the head portion. Accordingly, the transmitting assembly can be engaged with and separated from a driving member of an electronic image forming apparatus with ease and smoothness.