Abstract: This paper deals with the design and implementation of human-machine interface of military Command and Control Simulation System (C2SS) on SUN3/60c workstation. It has the following features: having comparatively-high fault-tolerance capability, and providing several operation methods, such as control panel, menu and keyboard input, It is very convenient for different operators. This human-machine interface is flexible, expansible and consistent. It provides a good development approach for military commander getting information from the system, inputing information into the system and forming human-machine interface rapid prototype.