A method for transmitting a Channel State Information (CSI) reporting at a user equipment (UE) in a wireless communication system is disclosed. The method includes transmitting a rank indicator (RI) and a first type precoding matrix indicator (PMI) to a base station (BS) according to a first CSI feedback type; transmitting a second type PMI to the BS according to a second CSI feedback type, wherein the RI and the first type PMI are jointly coded, and transmitted through a physical uplink control channel (PUCCH), wherein the RI and the second type PMI are not jointly coded, and transmitted through the PUCCH, wherein a transmission period of the first type PMI is different than a transmission period of the second type PMI, and wherein the transmission period of the first type PMI is longer than the transmission period of the second type PMI.