A method for transmitting downlink reference signal in a multi-antenna wireless communication system is disclosed. The method includes allocating RSs for a first antenna group to a subframe having a predetermined area with different access levels for user equipments having different access capabilities, pairing RSs for a second antenna group with RSs for the first antenna group, allocating the paired RSs to the predetermined area of the subframe in code division multiplexing, and transmitting the subframe on the downlink.