According to an embodiment, the present invention includes : a trader terminal used by a trader for an apartment house, and registering trade mediation request information, including a trader name, a trader contact number, apartment house information, and trading types such as selling/buying/renting/leasing, in an apartment house trading server by accessing the server through the Internet; the apartment house trading server receiving and registering a contact number of a terminal of a real estate agent in charge of trading each apartment house, and transmitting the trade mediation request information to the terminal of the real estate agent in charge of a requested apartment house trade when receiving the trade mediation request information from the trader terminal; and the real estate agent terminal mediating the trade assigned by the apartment house trading server, and displaying the trade mediation request information received from the apartment house trading server. As such, the present invention is capable of providing available information to traders excluding false information.(100) Apartment house trading server(300) Trader terminal(AA) #1 apartment house(BB) #2 apartment house(CC) #3 apartment house(DD) #1 real estate agent terminal(EE) #2 real estate agent terminal(FF) #3 real estate agent terminalCOPYRIGHT KIPO 2018