A user terminal supports a D2D proximity service enabling a direct device-to-device communication without passing through a network. The user terminal includes a controller configured to select one of a plurality of other user terminals as a D2D synchronization source and to synchronize to a D2D synchronization signal transmitted by the D2D synchronization source, when the user terminal receives D2D synchronization signals transmitted by the plurality of other user terminals in a case where the user terminal is out of network coverage. The controller stops transmission of a predetermined D2D synchronization signal in response to selecting the other user terminal as the D2D synchronization source, when the user terminal is transmitting the predetermined D2D synchronization signal in a case where the user terminal is out of network coverage.