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.