PROBLEM TO BE SOLVED: To provide a GPS synchronous base station and a base station synchronization system that reduce the deviation of frame timing in air synchronization at a time of the occurrence of communication failure with a GPS satellite and is able to suppress interference caused by the deviation.SOLUTION: GPS synchronous base stations 104a-104v according to the invention are configured to maintain frame timing by air synchronization referring to control signals from peripheral base stations if a 1PPS signal cannot be received, and selects a base station of a higher order as a synchronization destination of air synchronization from among peripheral base stations performing air synchronization if all the peripheral base station perform air synchronization.
