An integrated document management system comprises a storage unit which
stores therein a document database consisting of a plurality of documents
based on a hierarchical structure and a management information database
consisting of a information indicating a relation between a document in
an upper layer and a document in a lower layer and a plurality of
management information including information on a version number of each
document. A server is connected to the storage unit and is provided with
the manager of the documents. A client is connected via a network to the
server and retrieves, by accessing the server, a document in the upper
layer and a document in the lower layer each having a specified version
number according to the management information.