A method of transmitting a reference signal for a hybrid beamforming in a base station of a wireless communication system according to one embodiment of the present invention may include selecting first subset elements arrayed in a first direction from a plurality of antenna elements included in a 2D array antenna of the base station and transmitting a first reference signal through a reference beam formed by the first subset elements, wherein a first cross-section for the first direction of the reference beam corresponds to a directional beam and wherein a second cross-section for a second direction crossing the first direction of the reference beam corresponds to an omni-directional beam.