The present invention relates to a method and an apparatus for transmitting a reference signal by a transmitting side in a wireless communication system supporting multiple antennas. Specifically, the present invention comprises a step of transmitting a first reference signal for a plurality of first domain antennas and a second reference signal for a plurality of second domain antennas, wherein the second reference signal is used for antennas included in the second domain antennas except for antennas included in the first domain antennas and a particular antenna port, and the particular antenna port is selected from antenna ports included in multiple antennas except for the first domain antennas and the second domain antennas.