PURPOSE : A real estate deal support system and a control method thereof are provided to store additional service applying information about a real estate deal and update data about a processing data of a corresponding additional service provider, thereby checking the processing state in real time.CONSTITUTION : A plurality of member brokerage agency computers(10-1, 10-2, 10-n) outputs information necessary for a real estate deal and an additional service to a real estate deal support server(20). The real estate deal support server stores information necessary for the additional service and the real estate deal in a service pack DB(30). The real estate deal support server stores transmission data in the service pack database wherein the transmission data including data for a processing state of the additional service.COPYRIGHT KIPO 2012