The goal of this research is to construct a system with the ability of helping decision makers make decisions while facing emergency or disaster evacuation conditions, that is, to build a decision support system for mass evacuation and emergency management. By combining MASSVAC2 and HEUPRAE2 analysis models, shortest path finding technique, computer graphic display technique, data structure and processing algorithms, and interactive computer dialog method, a system named Transportation Evacuation Decision Support System (TEDSS) has been built to achieve the goal of the research. TEDSS has been proved to be very useful and practical after it is applied on the Virginia Beach City flood evacuation project and the Mexico City earthquake project. A description of the structure of TEDSS and the theoretical and technical aspects behind it is included. There is also a manual of how to use TEDSS can be found in chapter 5. / M.S.