Disclosed in the present invention is a method for a user equipment reporting channel state information to a base station in a wireless communication system. The method for reporting CSI comprises the steps of: receiving, from the base station, a channel state information-reference signal (CSI-RS) defined by at least two antenna ports; estimating the rank of a downlink channel based on the CSI-RS; configuring a plurality of precoders corresponding to the estimated rank with at least two precoder groups; calculating a channel quality indicator under the assumption that the at least two precoder groups are rotationally applied to at least one resource block unit, wherein precoders included in the precoder groups rotationally applied to the at least one resource block unit is rotationally applied to at least one resource element unit; and reporting the CSI including the calculated CQI to the base station.