A method for reporting channel status information (CSI) to a base station by a terminal in a wireless access system is disclosed in the present application. The method comprises the steps of: receiving information on one CSI process including a plurality of reference signal resources from the base station; receiving reference signals corresponding to the plurality of reference signal resources from the base station; selecting two or more reference signal resources among the plurality of reference signal resources on the basis of the received reference signals; and reporting the CSI corresponding to the one CSI process to the base station, wherein the CSI includes indicators indicating the two or more reference signal resources.