Proposed are a method and an apparatus for receiving an MU PPDU in a wireless LAN system. Specifically, a receiving STA receives an MU PPDU from a transmitting STA. The receiving STA decodes the MU PPDU. The MU PPDU includes an LSIG field, an RL-SIG field, an HE-SIG field, and an EHT-SIG field. A first reserved bit of the L-SIG field includes information indicating that a first band in which the MU PPDU is transmitted is greater than 160 MHz. A second reserved bit of the HE-SIG field includes information relating to a second band in which the EHT-SIG field is transmitted or the size of the first band. The receiving STA includes an HE STA and an EHT STA.