Abstract: In order to develop precision agriculture technology for wheat, a decision-making system for wheat precision fertilization based on WebGIS, basing on soil testing and formulated fertilization with Web Services, metadata, spatial interpolation and AJAX technology, running on .NET, was produced with software VS2005 ArcGIS 9.3 and SQL Server 2005 in this paper. A four-layer framework has been adopted in the system which has the function of information querying and positioning, precision fertilization, prescription information publishing and sharing etc. After analyzing the precision fertilization data on wheat from 22 villages and towns in Huaxian city of Henan province, the system successfully offered a decision for wheat prescription information and published it on the web in a real-time way which directly makes the drawing, generating and publishing of prescription map to a semi-automatic level. It has been proved from this experience that metadata-based prescription map can be shared among systems and data sources freely without being limited to GIS platform.