In a network where a person who wants to sell an estate is connected to an estate purchase broker so that data communication can be performed, there is provided a database of information on estates to be sold which are provided by a person who wants to sell an estate, an estate purchase broker, and the like. An estate group purchasing matching system includes search condition setting means for analyzing a purchase condition described by a person who wants to purchase an estate and his/her attribute information and setting a condition for searching a person who roughly corresponds to it. In the search condition set by this search condition setting means, a priority degree of condition is quantified for each of the items and a search condition having a certain width is set for each item value. Thus, it is possible to extract a plurality of registered candidates who want to purchase an estate from the database containing estate purchase desirer information connected to the network by estate purchase desirer brief extraction means.