A method and apparatus for maintaining association in a WLAN system are disclosed. The method for performing association by a station (STA) in a wireless LAN (WLAN) system includes: transmitting an association request frame from the station (STA) to an access point (AP); and receiving an association response frame from the access point (AP) in response to the association request frame. If the association request is accepted by the access point (AP), the association response frame includes information regarding an association comeback time.