The present invention relates to a wireless communication system and, in particular, to a method and apparatus for transmitting/receiving a feedback trigger frame in a wireless LAN system. The method for transmitting a feedback trigger frame by means of a request station (STA) in a wireless communication system according to one embodiment of the present invention includes the steps of: transmitting the feedback trigger frame including an acknowledgement (ACK) indication field to a response STA; and receiving a feedback frame from the response STA, wherein the ACK indication field can be set as a value indicating a first type associated with ACK, a second type associated with block ACK (BA), a third type associated with no ACK, or a fourth type associated with an ACK other than those of the first, second, and third types.