Proposed are a method and apparatus for performing sensing in a wireless LAN system. In detail, a first STA broadcasts a sensing request frame. The first STA receives a first sensing response frame form a second STA and receives a second sensing response frame from a third STA. The sensing request frame includes STA identifier information and RU allocation information. The STA identifier information includes identifiers of the second and third STAs. The RU allocation information includes information about a first RU allocated to the second STA and information about a second RU allocated to the third STA. The first sensing response frame is received through the first RU. The second sensing response frame is received through the second RU.