A wheel mouse includes a first scroll wheel, a second scroll wheel, a first encoder, a second encoder and a control unit. The first encoder generates a first rotation signal according to the rotating condition of the first scroll wheel. The second encoder generates a second rotation signal according to the rotating condition of the second scroll wheel. The control unit is electrically connected to the first encoder and the second encoder for executing a corresponding function in response to the first rotation signal and the second rotation signal. The control unit executes a first function when only the first rotation signal is generated. The control unit executes a second function when only the second rotation signal is generated. The control unit executes a third function when the first rotation signal and the second rotation signal are simultaneously generated.