Abstract: The development of air environmental quality model is an important part of the development of environmental decision support system.A Gaussian trajectory plume model,which has the advantages of both plume model and puff model and consider the case of static wind conditions,is thus established,especially for the air pollution diffusion in complex terrain and complex air flow regions,such as Qingdao and Guiyang cities.The model is verified to be very suitable to the actual monitoring data obtained from the two cities.