Provided are white space sharing control method, database device, agent device and communication system with which use of white space (WS) is controlled when a plurality of WS wireless devices compete for use of WS. In ST105, an application A proxy device arbitrates WS channel use requests received from a plurality of application A first WS wireless devices and combines these requests into one, and, in ST107, the application A proxy device transmits the arbitrated WS channel use request and location information to a frequency database apparatus. In ST108, the frequency database apparatus decides whether or not application A and application B are available on the basis of the “arbitrated WS channel use request and location information” and “priority ranking information according to use”. In ST109, the frequency database apparatus updates application A database information and application B database information on the basis of the decision result.