For more than twenty years, the PC technology has been widely in hydrologic data processing. At resent, as application of the new apparatus and the new scientific technology in hydrology, it is necessary to develop a kind of hydrologic data processing software in the windows system, with the characteristics of friendly interface and easy operation. The south-region hydrologic data processing software has been developed with the visual programming language of Microsoft Visual Studio (Version 6.0). This paper expatiates the software developing purpose, designing ways, technique courses and system realizations.