Disclosed in an embodiment of the present invention is a method for transmitting channel state information and device thereof. By applying the technical schemes of the embodiment of the present invention, in a LTE-A system using PUCCH reporting mode 1-1, in a situation where PMI feedback for 8 antenna ports is needed to be reported in a sub-frame and PUCCH capacity is limited, therefore codebook compression is required, a corresponding relationship definition of the pre-coding matrix indicator information or the pre-coding matrix indicator information pair and the codebook index or the codebook index pair after codebook compression is provided, thus realizing the feedback and receiving of channel state information between a base station and terminal equipment.