Abstract: This paper outlines the basic Atmospheric Diffusion Models (ADM) and integrated models which are based on the principle of selecting models in CZEMIS. The principle of software engineering is adopted to make the structure design for ADM and a software package is established. The pollutant distribution for different metereological conditions, different location and emitting feature of pollution sources, and the average of different period can be obtained with the help of the package. This package can also be used to examine the accuracy of models, adjust parameters, and give graphics to indicate the pollutant distribution.