The present disclosure relates to an apparatus and a method for transmitting and receiving channel state information of a User Equipment that supports 256-state quadrature amplitude modulation (256QAM). The method may include: receiving a reference signal for measuring channel quality from a base station; measuring the channel quality based on the reference signal, and selecting a CQI index value from a predetermined CQI index table including CQI index values for 256QAM modulation, based on the measurement result of the channel quality; and transmitting channel state information including the selected CQI index value to the base station.