A method for transmitting a channel state information reference signal (CSI-RS) in a specific downlink subframe having an extended cyclic prefix (CP) in a wireless communication system according to an embodiment of the present invention includes: generating a CSI-RS sequence and mapping the CSI-RS sequence to CSI-RS complex-valued modulation symbols; and mapping the CSI-RS complex-valued modulation symbols to at least one pattern of a first CSI-RS pattern set composed of a plurality of CSI-RS patterns and a second CSI-RS pattern set composed of a plurality of CSI-RS patterns, the CSI-RS patterns being composed of REs to which CSI-RS complex-valued modulation symbols are mapped, wherein the second CSI-RS pattern set is available when 2 OFDM symbols are used for a physical downlink control channel in the downlink subframe or a specific downlink control information format is configured.