Abstract: The ideas and methods to computerize the integrated catchement arrangement system for multi-source irrigation projects in irrigated regions were evolved by means of basic theories of graphics in computer database. Aimed to maximize the supply of water for a whole irrigated region and based on the optimized use of a single reservoir or water source, the mathematic models were established for the integrated catchment arrangement system; the techniques of database, searching techniques of visualization and the techniques of visualized programming were adopted to probe the methods on computer to realize the integrated catchment arrangements for multi-source irrigation projects. The catchement of Weihe River was taken as an example of water sources to search for the answers to the mathematic models set up for the integrated catchment arrangement system.