The approach presented here concerns ontologybased
retrieval of information bases. We picture that
information management is divided into three layers. The
top layer is composed of domain ontologies and metadata,
the middle layer consists of topic of information object
and metadata description of the information object, the
third layer is network concrete unstructured information
and information resource. There are two retrieval patterns
in the retrieval structure, one is concept-matched retrieval,
which is help users to locate the concept of the
information, the other is iterated retrieval which help
locating the most related information of the user step by