A method and apparatus for performing a beamforming training for a multiple input multiple output (MIMO) operation in a wireless local area network is provided. The apparatus assigns at least one of a plurality of sector groups with respect to each of a plurality of array antennas. The apparatus determines a sector used for a data transmission during a sector sweep by transmitting a plurality of sector sweep messages in the plurality of sector groups through the plurality of array antennas to responders simultaneously.