The present invention has an object to provide a wireless communication apparatus and a wireless communication method, which are capable of measuring line qualities as to a plurality of channels in a high efficiency without giving an adverse influence to communications made by other mobile stations in such a case that a mobile station is communicated with a base station via a relay station.In a frame 1, a mobile station “MS” transmits a packet “MS(1)” via a channel “CH1” to a relay station “RS”, and the relay station “RS” transmits a packet “RS[MS(0)]” via a channel “CH2” to a base station. In this case, symbol “MS(1)” indicates a first packet of the mobile station “MS.” Also, symbol “RS[MS(0)]” represents a packet which is relayed by the relay station “RS.” Next, in a frame 2, the channels “CHs” of the frame 1 are traded with each other, and then, packets are transmitted via the traded channels “CHs.” In other words, the mobile station “MS” transmits a packet “MS(2)” via the channel “CH2” to the relay station “RS”, and the relay station “RS” transmits a packet “RS[MS(1)]” via the channel “CH1” to the base station. When the above-described channel trade is performed, the qualities of the channels “CHs” between the mobile station and the relay station can be measured as to the channel “CH1” in the frame 1, and as to the channel “CH2” in the frame 2 by the relay station. As a consequence, it is possible to immediately grasp that the line qualities have been deteriorated.