Abstract: Based on the superiority of web services technology and the difficulty in share of the crop simulation models, the author brings forward an integrated system framework established on the basis of web services and GIS. The author also accomplished the web service to simulate crop yield and developed a system under the framework successfully, which has been applied into the Yangou basin in China. The practice shows that it is feasible to put the web services into the use of crop simulation, which is in favor of system integration and share of the crop models for the whole society.