Disclosed herein is a method of sending and receiving (or transceiving) audio stream in a wireless communication system. The method performed by a first device includes receiving reference codec information from a second device, performing an audio codec negotiation procedure for determining an audio codec to be used to send and receive audio stream to and from a third device, checking whether the audio codec determined through the audio codec negotiation procedure is identical with the audio codec supportable by the second device, and operating in bypass mode or conversion mode based on a result of the check.