The present invention discloses a method for Multiple Input Multiple Output (MIMO) channel information feedback, and the method includes: a terminal selecting part of column vectors for MIMO system feedback from a codebook matrix W corresponding to a Precoding Matrix Indicator (PMI) and marking the selected part of column vectors as Wpart; the terminal determining information O which represents high-precision vector quantification information of MIMO along with the part of column vectors Wpart according to a common representation relationship F, and feeding back the information O to a base station. The present invention also discloses a terminal and a base station which support MIMO. The present invention achieves high-precision and low-overhead channel information feedback and can well support multiple vector feedback needed by high rank (more layer multiplexing) MIMO transmission and high-precision feedback needed by low rank MIMO transmission simultaneously.