PROBLEM TO BE SOLVED : To solve a problem of taking fair time for finding a desired property of a buyer and a tenant due to retrieval while clicking a summary though easily retrieving a real estate property in points of being executable at home by using the Internet.SOLUTION : This periodically patrolling automatic matching system of information between two groups being a Web site 4, is provided with a database 41 for storing desired information of a first information provider, a database 42 for storing desired information of a second information provider, a periodically patrolling automatic retrieving means 43 for retrieving the respective desired information in a desired information database of the second information provider with every specific period from the whole desired information of the first information provider, a matching means 44 for determining whether the respective desired information of the second information provider in the retrieval and the desired information of the first information provider are completely coincident or vaguely (fuzzily) coincident, and an automatic mail transmitting means 45 for transmitting the coincident information to the first and second information providers by mail when there is the coincident information by the matching means.