Ordering is properly performed for document databases registered in an associative search server. In an associative search server capable of performing an associative search by correlating a plurality of document databases, the history of the associative search is stored as an associative search recording table by associative search recording table storing means. By using this associative search recording table, a showing order of document databases presented by document database selecting means is properly set by showing order changing means. Alternatively, by registration fee calculating means, calculation is properly carried out as to registration fees of the document database registered in the associative search server.