Abstract: Current networking and Internet technologies have made CAD／CAM activities changing from traditional single-user application to multi-user collaborative application．Within a spatially distributed，network-centric collaborative design environment，real-time data exchange and product model synchronization become a key problem for collaborative geometric design．In this paper，we propose a new approach for replicated collaborative feature-based modeling．This new approach combines feature-based modeling technique with distributed computing and network communication technologies．It implements incremental collaborative modeling based on simple modeling operations message exchange．This new approach can realize real-time data exchange and model synchronization for collaborative design effectively．We also introduce collaborative modeling communication protocol，modeling object reference and collaborative modeling system in detail．