By introducing the process algebra to the work of describing DSS model system , a new paradigm , called DSS model algebra , for modeling DSS model system is proposed. There are some properties for model communication such as invocation , selection , repeat , synchronization and concurrence involved in the new paradigm. The imple2 ment technology is also discussed. By comparing the DSS model system based on model algebra and model systemof components , it also gives an implement example for model system based on components.