Abstract: Heilongjiang Province was taken as an example to build a network system of favored trees for suitable land by using forestry spatial information technique which can run on the platform of Internet networks. Through comprehensive analysis and processing of forestry spatial information data, an overlapped vector layer with main forestation factors will be generated. It is useful for visual query by using Digital Elevation Model(DEM) overlapped with remote sensing images. At the same time, a network database of spatial information and forestation expert knowledge was built in order to adapt on the network environment. The system programmed by using the object model of ESRI ARCIMS, which realized to merge the multi sources data including forestry spatial information and expert knowledge base etc., as well as the network expression, analysis and decision of spatial information.