To return an optimum URL that is accordant with every client environment by supplying the URL information to a client in accordance with the client environment, the environment of a server to which the client is connected or the network environment.

A retrieval request is received from a client (401) and the URL information is retrieved from a URL information data base in response to the retrieval request (402). A URL information list of retrieval results is converted according to the environment of the requester client and by referring to a URL conversion table 413 (403). The converted URL information list is shaped into a form that can be displayed at the client side (404). Then the shaped URL information list is sent to the client to end this processing (405). Thus, an optimum URL can be returned in accordance with every client environment.