A method and apparatus for receiving a PPDU in a wireless LAN system are proposed. Specifically, a receiving STA receives a PPDU from a transmitting STA through a first band, and decodes the PPDU. The PPDU comprises first to third fields. The first field comprises information on the bandwidth of the first band. The second field comprises information on whether preamble puncturing is performed in the first band. The third field comprises information about a pattern of preamble puncturing.