A feedback method of a user equipment in an open loop Multiple-Input Multiple-Output (MIMO) system is disclosed. The method includes, receiving one of a plurality of modes determined according to types of resources to be used for performing feedback from a base station, and selecting a precoding matrix from a codebook subset corresponding to the received mode, applying the selected precoding matrix, and transmitting feedback information. Different codebook subsets are configured with respect to the plurality of modes, and the codebook subset is configured by extracting a predetermined number of elements from a base codebook based on a predetermined criterion considering the characteristics of the modes.