A method for Channel State Information (CSI) reporting in a wireless access system which supports a carrier aggregation, the method performed by a user equipment (UE) includes measuring a first type CSI for a first component carrier (CC) of two or more downlink (DL) CCs; measuring a second type CSI for a second CC of the two or more downlink (DL) CCs; and reporting the first type CSI only, when a collision of a report of the first type CSI with a report of the second CSI type is occurred in a same subframe, wherein the first type CSI includes (1) a Rank Indicator (RI) and a first Precoding Matrix Indicator (PMI), (2) only the RI, or (3) only the first PMI, and wherein the second type CSI includes (1) only a SubBand (SB) CQI or (2) the SB-CQI and a second PMI.