Abstract: Geographic information system (GIS) succedssfully linked to air pollutant diffusion data was introduced to the field of multi-source air diffusion,which realized the functions of computerized visualization of air pollutant diffusion data and direct cartography.On the basis of this,an air pollution diffusion spatial information system software package was developed with the functions of GIS graphic processing and analysis.The package improved the traditional G-H model of area source and enhanced the computation speed and accuracy.The line source mode was also improved with increased computation speed and accuracy,thus realizing the use of PC for line-source pollution diffusion modeling.