Disclosed are a method and apparatus for transmitting a training field. The method for transmitting a training field in a wireless LAN system comprises the steps of: transmitting additional long training field (LTF) indication information; and transmitting a frame including the additional LTF and partitioned data fields. The additional LTF comprises a field for demodulating the partitioned data fields included in the frame, the additional LTF indication information includes information on the location of the additional LTF included in the frame, and the partitioned data field includes at least one sub-field. Accordingly, the present invention can enhance channel estimation performance.