A cell search method of a terminal in a wireless communication system, comprises: a step of receiving a narrow band synchronization signal through a narrow band from a base station; and a step of acquiring time synchronization and frequency synchronization with the base station on the basis of the narrow band synchronization signal and detecting an identifier of the base station, wherein the narrow band has a system bandwidth of 180 kHz and includes twelve carriers arranged at intervals of 15 kHz, and the narrow band synchronization signal consists of a first narrow band synchronization signal and a second narrow band synchronization signal, wherein the first narrow band synchronization signal can be transmitted in a sixth subframe of a radio frame and the second narrow band synchronization signal can be transmitted in a tenth subframe of the radio frame.