A method for receiving system information in a wireless communication system supporting a Narrow Band (NB)-Internet of Things (IoT), the method performed by a terminal comprising: receiving a narrowband synchronization signal (NBSS) through a narrowband (NB) from a base station; acquiring, based on the NBSS, time synchronization and frequency synchronization with the base station; and receiving the system information related to the NB-IoT through a narrowband physical broadcast channel (N-PBCH) from the base station, wherein the system information includes at least one of operation mode information indicating an operation mode of an NB-IoT system or control information indicating an index of a legacy CRS (cell-specific reference signal) sequence, and wherein the control information is associated with a PRB (physical resource block) index of a PRB to which the legacy CRS is transmitted.