In order to simulate and real-time monitor the abrupt air pollution dispersion, we built a web environment information system (Web-EIS). Firstly, we chose Gaussian model to simulate the dispersion of air pollution. Secondly, the coordinate transformation from GPS system to Web map system was calculated. Thirdly, we used corresponding lines to indicate the densities of pollutants. Finally, an air pollution accident case was studied to verify the modeling algorithm and the system’s usability.