An inter-base station synchronization system is constructed without using any receiver for detecting a frame period error at a zone boundary between leaky coaxial cables, and without using any exclusive line or dedicated radio waves for use in transmitting the frame period error information from this receiver to base stations. This system has a plurality of base stations provided in certain intervals, leaky coaxial cables laid down between the base stations, and one, or a plurality of, mobile station that measure a time delay difference of received signals from adjacent ones of the base stations while the mobile stations move along zone boundaries between leaky coaxial cables, and that transmit the delay time difference information through the leaky coaxial cables to at least either one of the two adjacent base stations.