A method and apparatus for transmitting and receiving narrowband (NB) synchronization signals. A base station transmits an NB secondary synchronization signal (SSS) indicating N NB cell identities assigned for NB Internet of Things (IoT) operation, a specific sequence generated by multiplying a base sequence with a cover sequence in element units is used for the NB SSS, wherein the base sequence is generated through a second Zadoff-Chu sequence having a length corresponding to a largest prime number less than a length L in a frequency domain, and the specific sequence is divisionally mapped to and transmitted in a plurality of orthogonal frequency division multiplexing (OFDM) symbols in elements each having a length M.