Abstract: The software of Decision Support System of rice precision cultivation in county scale taking Jiangyan city as a case was developed primarily by means of the principle and method of agriculture information technology. It had complete functions, abundant contents, strong practice and high graph productivity. The system covered many contents such as precision quantity of base seedling, precision N application, precision irrigation, precision yield measuring, meteorological database and brainpower learning and so on. It also had base GIS spatial analysis functions such as an e-map guide, overlay analysis and spatial data query and so on. In practice, its functions was useable, dependability, simplification, the users are very satisfied with it.