PURPOSE : A real estate transaction method and system is provided to check an identity of transactors for a safe transaction, and to make a transaction of a real estate between only transactors receiving a password.CONSTITUTION : The method comprises several steps. First, a real estate seller or buyer requests a real estate transaction service to a server over a network(S11). The server transmits authentication data, input by the seller or the buyer, to a certification authority for checking the identity of the transactors(S12). The seller, approved by the authentication authority, registers data on the real estate at the server(S13). The buyer searches for desired data on the real estate among the registered data by using various search schemes(S14). The buyer selects at least one registered real estate among the searched data, and requests the server to connect to the corresponding registered seller(S15). The server notifies the seller of the buyer' s connection request(S16). Finally, the server sends the buyer and the seller a password for directly connecting to each other. Either the buyer or the seller makes a phone to an ARS(Automatic Response System), then inputs necessary data to the server via the ARS, and makes a phone connection to the seller or the buyer if the input password is approved(S17).? KIPO 2003