The present invention relates to a wireless communication system, and a method and apparatus for controlling channel access in a wireless LAN system. The method for controlling the channel access of a station (STA) of a wireless communication system according to the present invention comprises detecting a short frame transmitted by another STA; and deferring the channel access of the STA by a predetermined length of time. The short frame is a frame that triggers a service period during which the transceiving of a plurality of data frames of the other STA is allowed. The predetermined length of time can be set to the value corresponding to the length of time ranging from the start of the service period to the point in time at which the transceiving of a first data frame from among the plurality of data frames of the other STA is completed.