The present invention relates to a method and apparatus for feeding back channel state information in a wireless communication system supporting a three-dimensional multiple input multiple output (3D-MIMO) antenna. Specifically, the method comprises the steps of: receiving information on N beams, (where N is a natural number), precoded for specific antennas among a plurality of antennas constituting a 3D-MIMO antenna; selecting, from among the N beams, at least one specific beam for which to generate channel state information, and determining interference on the basis of M beams, (where M is a natural number, M≤N−1), among the remaining beams; and generating channel state information for the specific beam on the basis of the interference according to the M beams.