As many water conservancies were built in Qingfengsh an Basin in Jiangxi province， the situation of flood prevention in this basin is severe, so it is very necessary to construct the basin synthetic inquiry system based on GIS. From the purpose of the system, the system structure, function module and technology course of system development were analyzed, and the system data－flow organization and platform introduced. It is proved in practice of Qingfengshan Basin the system possesses advanced design, friendly user interface, powerful function, higher stability and practicability.