The present specification proposes a method for transmitting and receiving a signal, and an apparatus therefor, and more specifically, a method for transmitting, by a first station (STA), a signal to a second STA in a wireless LAN (WLAN) system, the method comprising the steps of: generating a training field including a basic training subfield for each spatial-temporal stream and a training subfield for each spatial-temporal stream on the basis of the total number of spatial-temporal streams, wherein the basic training subfield for each spatial-temporal stream is composed of M (M is a natural number) orthogonal frequency division multiplexing (OFDM) symbols on the basis of the information indicated by a header field; and transmitting a signal including the header field and the training field to the second STA through a corresponding spatial-temporal stream.