A method for transmitting, by a base station (BS), reference signals in a wireless communication system, and the BS therefore are discussed. The method according to one embodiment includes transmitting cell-specific reference signals on at least one first antenna port to a relay node (RN); and transmitting user equipment (UE)-specific reference signals on a second antenna port to the BS. A relay physical downlink control channel (R-PDCCH) is demodulated, by the RN, based on either the cell-specific reference signals or the UE-specific reference signals. A type of reference signals among the cell-specific reference signals or the UE-specific reference signals, which is being used to demodulate the R-PDCCH, is configured by a higher layer.