A method of transmitting channel information in a multiple antenna system includes receiving the channel information comprising rank information, and transmitting a confirm message through a downlink control channel as a confirmation for the channel information, wherein the confirm message comprises overriding rank information which overrides the received rank information in an open loop scheme and also comprises information indicating whether the received channel information is used without alteration in a closed loop scheme. A rank indicator (RI) and a precoding matrix indicator (PMI) can be carried on a dedicated control channel (DCCH) and be specified through a physical downlink control channel (PDCCH).