The present invention relates to 5G or pre-5G communication system for supporting a higher data transmission rate after 4G communication system such as LTE. The present invention provides a carrier aggregation method. A method of a base station, according to the present invention, comprises a step for: transmitting and receiving data to and from a terminal by means of a first carrier corresponding to a first bandwidth; transmitting to the terminal, by means of the first carrier, configuration information comprising information for an initial access to a second carrier corresponding to a second bandwidth; and transmitting and receiving data to and from the terminal by means of the second carrier on the basis of the configuration information.