The present invention relates to an exclusive intermediary transaction method between a customer and a licensed real estate agent through a network, a common intermediary using method between real estate agencies, and a recording medium storing a program thereof. The present invention relates to a real estate integrated information system capable of supplying a common intermediary between the real estate agencies, connecting and performing the exclusive intermediary between the customer and the real estate agency, and supplying information about real estate rental and real estimate properties for sale by connecting to the network using a mobile device like a smart phone and wired or wireless internet. The present invention relates to the real estate integrated information system and an operating method thereof, capable of providing an intermediary service with high quality through an exclusive intermediary request between the customer and the real estate agency, remarkably reducing the time and efforts of the customer, and smoothly and fairly performing the common intermediary between the real estate agencies.