A method is provided for receiving a downlink control channel in a wireless communication system. A user equipment performs a blind decoding in a first search space on the cell to find a first Physical Downlink Control Channel (PDCCH). The user equipment receives a Radio Resource Control (RRC) message including information on a second search space for monitoring a second PDCCH and identity information, and performs a blind decoding in the second search space on the cell to find the second PDCCH. The first PDCCH is demodulated based on a physical cell identity of the cell, and the second PDCCH is demodulated based on the identity information instead of the physical cell identity.