The present disclosure relates to a communication technique for fusing, with an IoT technology, a 5G communication system for supporting a higher data transmission rate than a 4G system, and a system therefor. The present disclosure may be applied to intelligent services, such as smart homes, smart buildings, smart cities, smart cars or connected cars, health care, digital education, retail, and security and safety related services, on the basis of 5G communication technologies and IoT-related technologies. A method of a terminal according to an embodiment of the present invention comprises: receiving an indicator for changing a bandwidth from a base station; identifying whether there is a signal to be transmitted on the changed bandwidth at a time of transmitting hybrid automatic repeat request (HARQ) ACK information for data received on a secondary cell (SCell) from the base station; and multiplexing and transmitting the signal and the HARQ ACK information in case that there is a signal to be transmitted in the changed bandwidth.