PROBLEM TO BE SOLVED : To provide a system for supplying auction services of real estate articles allowing discounting brokerage commission for both sellers and buyers and clarifying cost-effectiveness for real estate agents.SOLUTION : An auction article advertisement is posted on an article advertisement bulletin board for inviting bidders and bidding information containing the bidders is fed back to the real estate transaction brokers containing the sellers. Real estate transactions are intermediated among the sellers, the buyers and the brokers on the basis of the fed back information and changed to normal mediating selling using the Web not by the auction if they do not meet desired conditions of the sellers as a result of the auction. This method is for main players in the real estate transactions; the sellers, the buyers and the real estate agents, and to develop a new system converting needs of each party in each position into mutual merits with the other parties in different positions on the Web.