The present invention relates to a wireless communication system, and more specifically, disclosed are a method and an apparatus for transmitting or receiving a downlink signal by considering an antenna port relationship. A method for user equipment receiving a physical downlink shared channel (PDSCH) signal in the wireless communication system, according to one embodiment of the present invention, comprises the steps of: determining from the downlink subframe a resource element (RE) on which the PDSCH is mapped; and receiving the PDSCH signal based on the RE on which the PDSCH is mapped, wherein when the DCI is comprised according to DCI format 1A and the downlink subframe is a multicast broadcast single frequency network (MBSFN) subframe, the RE on which the PDSCH is mapped can be determined depending on cell-specific reference signal (CRS) location information, which is included in a PDSCH resource element mapping and Quasi co-location indicator (PQI) parameter set that is established by an upper layer.