For developing a GIS application software with strong functions, convenience use and friendly interfaces, an integrated crossplatform method was employed, i.e.,a communication acrossprocesses technology by which two or over two Windows application programs can simultaneously receive and transmit informations.By means of visual software development tool(Visual Basic 6.0)to develop practicable application program in frontplatform,using OLE Automation way to start geographic information system software in backplatform,the functions of geographic information system in the application program can be realized. In combination with an illustration on a river information system, a program to accomplish MapInfo functions is given.