A wireless power transmission system, and a method and an apparatus for allocating a communication channel and transmitting a power in the wireless power transmission system. If a target device configured to wirelessly receive power from a source device is detected, a controlling communication channel to be used for performing communication with the target device is selected. An initial control signal including an identifier (ID) of the source device and a channel fix command are transmitted to the target device through the selected controlling communication channel. The channel fix command includes a command requesting the target device to use the selected controlling communication channel. A charging power is transmitted from the source device to the target device through a magnetic coupling between the source device and the target device.