The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A method and an apparatus for operating a base station and a terminal in a wireless communication system using an unlicensed band are provided. The base station can determine at least one channel in at least one unlicensed band using one of a single channel operation and a multi-channel operation, acquire the at least one channel according to a data transmission request, and transmit a channel preservation signal until a start point of a first subframe transmitted on the acquired at least one channel.