The Citystar GIS-based Climatic Resources Service System is a platform on which the results of climatic resources from numerical simulation and statistical calculation can be displayed and queried. The climatic values at any grid, meteorological index of crops, GIS information, and statistical information of agriculture can be queried expediently. The planting regionalization of crops can also be made by the system. The system has been widely used in the function and framework adjustment of agriculture production in Beijing suburbs. It provides the leaders of the related departments with scientific bases for decision-making.