Abstract: With the development of aerial and spatial remote sensing technology of China,the ground receiving station stores and manages mass spatial data at TB level.Thus,the traditional distribution mode cannot meet the application demand.So as to meet the demand of network informazation,it is required that the mass spatial data be distributed,shared and processed on the special network.Functions as online browsing,distribution and processing of spatial data,especially the mass spatial data have become an important research orientation in geographic information service.The paper focuses on the principles and key technologies of mass spatial data online distribution system based on J2EE.An instance of mass image spatial data online browsing and distribution is given.