Disclosed are a wireless power transmitter capable of transmitting power wirelessly according to an impedance of an output side and a wireless power transceiver. There are provided a wireless power transmitter and a wireless power transceiver including: a wireless power transmitting unit converting input power into a preset transmission power and transmitting the converted input power wirelessly; and a controlling unit controlling a transmission of the transmission power according to a level of output impedance of the transmission power output from the wireless power transmitting unit.