Cloud computing is a very popular vocabulary in resent years. Along with the technical development and the expansion of market, the GIS is beginning to be integrated with other IT and gradually gets into the main current of FT application. In the cloud computing ages, GIS also faces a new opportunity and change. This text starts from the concept and system structure of cloud computing, discusseB the theory and key technique of cloud computing, and sums up the application of cloud computing in domestic and international geography information profession from the GIS angle.