A 5th generation (5G) or pre-5G communication system for supporting a higher data transfer rate than a 4th generation (4G) communication system such as long term evolution (LTE) is provided. A method and apparatus which perform communication in a wireless communication system using an unlicensed band, and a method in which a base station controls a clear channel assessment (CCA) timing in a wireless communication system using an unlicensed band are provided. The method includes determining whether to change CCA timing by comparing a number of at least one of continuous successes or continuous failures in a CCA with a predetermined threshold value and when it is determined that the CCA timing is to be changed, randomizing the CCA timing.