The disclosure provides a method of operating a distributed antenna system (DAS) interworking with a spectrum sharing system (SSS) including: transmitting, by a node unit of the DAS, DAS information to a management system entity (MSE); generating, by the MSE, linkage information based on the DAS information and radio service device (RSD) information received from at least one RSD of the SSS; transmitting, by the MSE, the interworking information to a system controller of the SSS; receiving, by the MSE, allocation information including a result of allocating shared radio resources to the DAS and the at least one RSD, respectively, according to the interworking information from the system controller; transmitting, by the MSE, the allocation information to the node unit; and operating, by the node unit, according to the allocation information.