The present invention relates to a method performed by a terminal in a mobile communication system, the method comprising: receiving, from abase station, a configuration message including information on a plurality of frequency bandwidths, receiving, from the base station, data on a first frequency bandwidth among the plurality of frequency bandwidths, receiving, from the base station, downlink control information (DCI) including an indicator for a second frequency bandwidth among the plurality of frequency bandwidths, performing frequency bandwidth switching to the second frequency bandwidth, and receiving, from the base station, data on the second frequency bandwidth. The present disclosure relates to a 5G or a pre-5G communication system to be provided in order to support a higher data transmission rate after a 4G communication system such as an LTE.