PURPOSE : A method for a realty trading business through a realty information sharing system is provided to share information with employees of the same business by sharing the realty information of each region with nationwide realtors registered as a member, and allowing unspecified and many persons to view the registered information freely.CONSTITUTION : If the member inputs the realty information through the online, the realty information is stored in a database server by classifying the realty information into each region/trading sort/realty sort(S33). The summary information of the registered information is transmitted as a mail by extracting a mail address from entire member information stored in the database(S40). If a download request signal is received from the member, an information file is transmitted(S42). The member stores the downloaded information file and publishes the information to general customers through an external display device.? KIPO 2005