A method by which a base station receives feedback information on beamforming in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: transmitting an omni-directional beam formed uniformly in all directions, on the basis of a non-precoded first signal; transmitting a plurality of directional beams through a plurality of antenna ports on the basis of second signals precoded in different directions; and receiving feedback information from a terminal, wherein the feedback information includes a gain difference between a first directional beam among the plurality of directional beams and the omni-directional beam, and an index of a first antenna port used in transmitting the first directional beam among the plurality of antenna ports.