The application of geographical data is extending to various fields rapidly. However

geographical data acquirement is very cost

so the sharing of geographical data is needed in order to save users expense. There are many excellent works about raster data sharing in multimedia field

but vector data

especially very large volume geographical vector data sharing is rare. This paper discusses several problems about geographical data sharing in distributed environment. The first is data management in server

which need manage various data and utilize spatial data structure to support efficient data retrieval. The second is the data transportation between server and client

very large data volume and realtime response to user operation require that meet users maximum need by the minimum data transformation. The third is geospatial data visualization that provides information but only data. The last is the data safe problem

which including data control

digital signature and data watermarking technology.