Abstract: A knowledge based system integrated in the "MIS-oriented CASE" for improvement of software structures is discussed in this paper. Although software engineering sets up the optimization task of software structures for software developers andsome heuristic principles are proposed for use, the quality of software structure variesfrom developer to developer owing to their different experience and comprehension.This study is intended to explore some methods and make tools in order to improve quality of software structures and increase intelligent level of software engineering environment.