The "information system for emergence decision on the earthquake prevention and disaster reduction in Shanghai City" based on GIS technology is introduced. This information system consists of 7 functional modules. Mainly they are basic information of seismology and geology, subsystem of rapid evaluation for damage loss from earthquake, subsystem of decisive information for earthquake emergence, information query, maintenance and management of system, and etc., Meanwhile, the software application technology, such as color infrared aerophotograph, remote sensing and etc., and point out that the information system is needed to be improved in some aspects.