To enable a proxy server system to dynamically change its proxy servers on demand of a client for access without changing the setting of the server or the client, while taking a communication load imposed on each of proxy servers into consideration.

A proxy server system is composed of a plurality of proxy servers, and the proxy servers are capable of communicating information concerning connections between the proxy server and a client or between the proxy servers from one to another and vice versa. When the proxy server receives a packet of demand of a client for access, the proxy servers communicate the content of the client's demand for access and information on connections from one to another and vice versa, and the proxy server other than one who receives the demand of the client for access relays a reply, corresponding to the state of the proxy servers.