The incidents of United States Ship (USS) Stark and USS Vincennes during the Iraq and Iran war made US navy realize that it was a big challenge to make efficient tactical decision under real combat pressure. US navy started a number of programs applying humancomputer interaction (HCI) technologies to deal with it, such as TADMUS. An interface of a prototype decision support system (DSS) from TADMUS program was analyzed, and the system was successfully tested by US navy tactical officers in shipboard aegis combat systems combat information center. Some command and control (C²) systems design suggestions were studied to enhance the commanders' awareness of the tactical situation, which in turn contributed to greater confidence, lower workload, and more effective performance.