Modern-day products are usually designed cooperatively by groups of experts, each with his own areas of expertise. Because of different viewpoint, evaluation standard and domain knowledge of these design groups in collaborative design system, conflict is unavoidable. In this paper, an integration conflict management system (ICMS) was presented from the aspect of all life cycle. A hierarchical constraint network was introduced to detect the conflicts. Three conflict types were classified in ICMS and different type of conflict was submitted to different resolution strategy, constraint relaxation to data conflict and knowlegdge based reasoning to knowledge conflict or schema conflict. To those conflicts hard to be resolved with the above two strategies, an arbitration was used for the conflict resolution. ICMS also provided interface with other collaborative systems such as CAE, CAD to improve the efficiency of collaborative design system.