The characteristics of urban air quality are analyzed in detail by means of the meteorological and environmental data. The results indicate that the high frequency of the sandy weather is the prime reason that made air quality worse. The shorttime and shortterm forecast equations of sandstorms and the statistical and latent equations of air quality are built up for different season s and different periods of time, respectively. It is proved by tests that the the systen performs well. The Fortran and VB languages are used in the design of the programs and the establishment of the air quality forecast system for Wuwei. This system includes three parts: the sandstorm forecast, earlywarning and service system; the air quality statistical forecast system; and the air quality potential forecast system. The interface designed by the VB language is directly connected with the MICAPS system, and there are multiple functions such as data processing, dynamic statistical forecasting, potential forecasting model, as well as data collecting and processing, model running, forecast display, results distributing, date inquiring, prediction scoring, etc. The system is simple, userfriendly, fast, and easy to operate and has abundant functions.