The present invention relates to a method and an apparatus for transmitting, by a base station, a reference signal in a wireless communication system supporting a multi-antenna consisting of a plurality of horizontal domain antennas and a plurality of vertical domain antennas. Specifically, the method comprises the steps of: configuring, as a cell-specific reference signal (CRS) port, M first antenna ports among a total of N antennas that the base station has (where N and M are positive integers, N>M); transmitting a CRS using the M first antenna ports and transmitting a demodulation reference signal (DM-RS) using O second antenna ports (where O is a positive integer, N>O), to a terminal; and receiving channel measurement information using the CRS and the DM-RS which is fed back from the terminal.