Distributed collaborative design among heterogeneous CAD systems enables manufacturing organizations to maintain competitiveness in the fiercely competitive global industry. It is no doubt that the requirement of collaboratively heterogeneous CAD system is become more and more exigent. In this paper, a distributed collaborative design framework is presented and a prototype system of collaboratively heterogeneous CAD system is achieved by the Minimum Mapping Set (MMS). In this approach, the modeling operation corresponding to the modeling operations of each CAD systems are exchanged by neutral modeling commands(NMCs) in the form of XML to real-time transfer of parameters information including design intent between heterogeneous CAD systems. The prototype proves that our approach works well for integrating variously popular commercial CAD systems into a real-time collaborative design platform.