PURPOSE : A system and a method for a real estate intermediation information service is provided to offer the real estate intermediation information to a realtor opening no store through the mobile and the online, and offer trusted real estate intermediation information by determining safety of offered real estate.CONSTITUTION : A non-store realtor fixing module(170) fixes a non-store realtor to intermediate the offered real estate. An attested register copy analyzing module(140) analyzes the attested register copy of the offered real estate. A safety level determining module(160) determines transaction safety of the offered real estate. An offered real estate information registering module(110) registers client information and offered real estate information received from a client to a database(180). A current price calculating module(150) calculates a safe transaction price of the offered real estate by searching current price information of the offered real estate. The database stores member information, the offered real estate information, the current price information of the offered real estate, and general terminologies.? KIPO 2006