A method and apparatus for transmitting/receiving a downlink channel in a wireless communication system are provided. A downlink control channel and a downlink data channel corresponding to the downlink control channel are transmitted/received within a transmission time interval (TTI). A reference signal (RS) of an antenna port used for transmission of both the downlink control channel and the downlink data channel is transmitted/received on an OFDM symbol with the downlink control channel, and an RS of an antenna port used only for transmission of the downlink data channel is transmitted in the remaining OFDM symbol(s) of the TTI.