Proposed is a method for determining transmission using a network allocation vector (NAV) in a wireless LAN system. Specifically, after a receiving device receives a trigger frame, which triggers an uplink multiple user transmission, from a transmitting device, whether to transmit an uplink physical layer protocol data unit (PPDU) corresponding to the trigger frame is determined using the NAV of the receiving device. In this case, if the NAV is established by an intra-basic service set (BSS) frame, whether to transmit the uplink PPDU is determined without taking the NAV into consideration.