A system for managing resources in a communication system including systems, which do not have a permission for a first frequency band, includes coexistence managers configured to, when a frequency band available for the systems is searched from the first frequency band, manage the systems for coexistence and frequency sharing of the systems in the available frequency band; a coexistence enabler configured to transmit and receive information of the systems and information of the coexistence managers; and a coexistence discovery and information server configured to support control of the coexistence managers over the systems, wherein the coexistence managers transmit and receive predetermined messages to and from the coexistence discovery and information server and the coexistence enabler, perform channel classification for the first frequency band, and determine operating channels of the systems on the basis of the channel classification.