Information sharing system using maps

System capable of giving a sense of unity or solidarity to a plurality of users sharing information is provided. Each of a plurality of client terminals includes a position information acquiring means. A management server updates user position information stored in a user database based on present position information of the respective client terminals. The management server reads a plurality of items of user position information contained in a predetermined range and a plurality of items of user information associated with the user position information contained in the predetermined range from the user database on the basis of the predetermined range of the map information read from a map database, and transmits them to the client terminals. The client terminal displays the items of user information at respective positions corresponding to the items of user position information on the map information in the predetermined range received from the management server.