A method by which a station (STA) transmits a hybrid automatic repeat request (HARQ) physical layer protocol data unit (PPDU) in a wireless LAN system supporting an HARQ process, according to one embodiment of the present invention, comprises the steps of: generating a HARQ PPDU including allocation information on a HARQ burst, which is unit data to which the HARQ process is applied, and a plurality of HARQ bursts; and transmitting the HARQ PPDU, wherein the HARQ PPDU includes a HARQ signaling (SIG) field of a physical layer for transmitting the allocation information on a HARQ burst, and the allocation information on a HARQ burst can include STA ID for each of the plurality of HARQ bursts, HARQ burst size information, HARQ process channel ID and information indicating, in a toggle manner, whether a transmission is a new transmission or retransmission.