In a method for supporting a short transmission time interval (sTTI) in a wireless communication system according to one embodiment of the present invention, the method is performed by a terminal, and comprises the steps of: receiving a reference signal for decoding a downlink channel; and decoding the downlink channel by using the reference signal for decoding the downlink channel, wherein the reference signal for decoding the downlink channel may be transmitted by using a pattern to which a frequency separation is applied, in the case of collision with a cell-specific reference signal.