PURPOSE : A system and method for searching a real estate for a sale based on a principal topographical building is provided to search a real estate for a sale by embodying lot numbers of a principal topographical building and an estate for a sale on map information and considering a traffic, a living institution, and a circumference environment based on the principal topographical building.CONSTITUTION : An administrative district DB(500) includes administrative district information. A geographic information DB(510) includes geographic information. An institution information DB(520) includes information of a principal topographical building. A real estate information DB(530) includes real estate information. A selling estate information DB(540) includes selling estate information. A client(560) connects to a web server(550) and the World Wide Web for using a real estate searching system. An application module(551) in the web server(550) is interworked with the above DBs and searches a selling estate based on a user-select administrative district and a principal topographical building, and supplies detail information to the user.? KIPO 2002