Artificial Intelligence（AI） technology and Geographic Information System（GIS） were integrated in this study. Deep researches on Intelligent GIS have been done. At the same time great agriculture macroscopic information realization has been trialed. General knowledge reasoning model and object-oriented knowledge bank expert system were used in this system. Based on GIS platform（MapInfo）, agricultural natural conditions classification system was developed by using object-oriented technology. Agricultural natural conditions in Jilin province were classified and a crop varieties combination model was studied, in which corn was given as an example.