Abstract: Requirements for dynamic architecture,flexible configuration and mobility of the synchronous computer supported collaborative design system are analyzed.A formalized model of the system is presented by using Multi-Agent,P-i calculus and Petri-net approaches.Based on Pi-calculus operating semantics,dynamic behaviors of the system are guaranteed.Based on Petri-net theory,fair and no deadlock floor control of the system with multilevel and multi-resource applications are realized.