Various object-oriented methodology is advocated in recent years. The Unified Modeling Language (UML), which is the unification modeling language ofthose notation, is becoming leading now. This paper proposes a supporting method ofdiagrams generation with the transformation rules in UML to draw diagrams eliminated contradiction in a short time by using common elements which other diagrams have. The validity of the proposal method is confirmed by implementing a diagram transformation editor as an experiment and verifying a part of the rules on the editor. The rules are extracted within an extent ofspecification of UML and used without any extension, semantics, and so on. Consequently, diagrams without contradiction can be generated in a short time. Especially, transformation of the diagrams which show the same character of a system such as the sequence diagram and the collaboration diagram expressing the interaction ofan object has generated the near completion diagram.