Abstract: With the increasing demand for querying images, the traditional Web querying system of remote sensing images can not meet the needs because of its shortcomings, including weak user interaction capabilities, slow responding speed of the server, and the poor offline operation ability. Furthermore, it is known that traditional querying system does not concern the needs of crops remote sensing monitoring. So a new satellite images querying system was set up based on Silverlight technology using LINQ and WCF technologies with a thought of multi-tier architecture, which can be applied easily to monitor crops growing via remote sensing. In this system, two fast-querying algorithms of both orbit-fixed and orbit-varied satellites were advocated, which not only can improve the system efficiency, but also enhance the system offline operation ability. The results show that, System response time?shorter?than the traditional?system?by 25%, meanwhile can reduce the server load. In conclusion, the new querying system has the ability of dealing with concurrent access by a large number of users in the same time. The system has good application prospects in fast Query of remote sensing images,?agricultural condition?monitoring and?crop yield estimation.