A method and device for sending a synchronization signal and a method and device for synchronization between base stations, include: determining, by a synchronization source base station according to a synchronization level of the synchronization source base station, a resource for sending an NLRS for clock synchronization between base stations, and according to the determined resource. In this way, one NLRS for clock synchronization between base stations is configured on each synchronization source base station, and the NLRS is sent on a resource determined according to a synchronization level, so that a synchronization base station that acquires the NLRS can determine the synchronization level of the synchronization source base station according to a resource for sending the NLRS.