According to the regulations of farmland gradation and the experiments in some provinces, the GIS-based software LandFD system was designed by using modern GIS and Database technology, which achieves the objective of being automatic and lucid to the users. The paper analyzed the database structure and the functions. The system have been used in Mingguang Municiplity, Anhui Province. The result shows that the technical procedure of the system is consistent with the principles of the farmland classification regulations. The software runs stably and enhances the efficiency of farmland gradation.