The air quality forecast & warning and pollutant diffusion emergency response system is developed by the Changzhou Meteorological Bureau and the Changzhou Environmental Monitoring Station jointly. It is a synthesized application system of environmental and weather analysis and research, which combines air quality forecast and pollutant diffusion emergency response together by setting up the website and using internet technology. The accuracy of the air quality forecast has been greatly improved since it was put to use in June 2008. The system is suitable for meteorological and environmental services for its property stability, convenience and transplantability.