The application of GIS technology to Military Environmental Information(MEI) management will play a vital role in MEI management, and can lead to better decision-making. This paper discusses both the management method and the application fields. Case studies, like information management, pollution coverage evaluating, military transportation planning and monitoring, and decision-making supporting, are presented in this paper. Detailed digital basemap database, Digital Elevation Model(DEM) data, Digital OrthoImage Model(DOM) data, image database of Remote Sensing, Social economic element database, and other informations related to military features, can be integrated into MEI GIS, and will meet the needs for later query and statistics. Spatial analysis is the bridge that links fundamental data models to GIS technology. While buffer analysis can be used for identifying the locations of hazardous chemical storage sites in relation to residents living area, and can facilitate the evaluation of the threatened area in the event of a leak or spill of hazardous materials. Network analysis can be used in military transportation planning and monitoring. GIS is particularly useful in providing composite visual representation of fairly complex underlying model calculations, analysts can draw implicit and important conclusion from the already known geographical data. The study shows that the management of MEI using GIS technology is reasonable and feasible, and GIS is a highly efficient tool in MEI management.