An exemplary electronic device is connected with an earphone. The earphone includes a first storage unit storing information as to functions of the earphone. The electronic device includes a second storage unit storing a function information table recording information as to user-controllable functions of the electronic device, function units corresponding to the user-controllable functions, an identifying module, and a control module. The identifying module retrieves the information as to functions stored in the first storage unit, and determines whether one or more of the controllable functions of the electronic device are controllable by the earphone. The control module activates all of the function units corresponding to the controllable functions of the electronic device which are controllable by the earphone, and controls one or more of the activated function units according to one or more control signals transmitted from the earphone to the electronic device. A related method is also provided.