Abstract: Geographic information system (GIS) is a newly developed technology based on computer.It is a technical system to realize the management and study of spatial data.An intersecting frontier science has been formed focusing on the research, development and application of this technology.GIS is a system that includes software, hardware and geographical data, as well as computer professionals.It is the key technology and core for the Digitalized Earth project, with the functions of collection, storage, management, analysis, descreption, display and application of the data on space and geographical distribution.The system is a technology about data analysis, combination and integration.It has been broadly used in geosciences with a great success.