A method and apparatus for reporting a downlink channel state are disclosed. The method for reporting channel state information (CSI) to a base station (BS) by a user equipment (UE) in a wireless communication system having frequency-selective inter-cell interference, includes: performing channel measurement in a frequency band configured for downlink channel measurement; and reporting downlink channel state information (CSI) in accordance with the downlink channel measurement, wherein the frequency band is independently configured for each information contained in the CSI, and thus the downlink channel measurement is performed in each information-specifically configured frequency band contained in the CSI. As a result, the method and apparatus can efficiently report downlink channel state information, such that a higher-quality communication environment is expected in a heterogeneous cell environment.