The present invention relates to a method and apparatus for transmitting channel state information (CSI) on a terminal having a plurality of cells allocated in a wireless communication system. The method includes the steps of: setting a plurality of cells as a plurality of groups, at least one of the groups including a plurality of cells; determining a priority for each of the groups; and transmitting multiple pieces of CSI for a top priority group having a highest priority from among the groups on the basis of the priority, wherein, when the top priority group includes two or more cells, the CSI includes each piece of CSI on each of the two or more cells.