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The features of spatial-temporal distribution of air pollutants in the urban area of Hohhot were analyzed using the monitoring data of pollutant density such as TSP, SO 2 and NOx in the urban area from 1990 to 2002 to study the relationship between pollutant density and meteorological conditions. Results show that the dominant pollutant in Hohhot is smoke; pollution is more serious in spring and winter than in summer and fall, similarly more serious in the heating period than in the non-heating period. The air pollution in the central Hohhot is most serious. The amount of pollutant emission and the atmosphere stability state are major factors that influence air pollutants in the urban area. The weather change is the dominant factor of the urban air pollution density change. The local circulation is also a key factor influencing pollutant distribution. Therefore, the variations in exhaust gas in different seasons along with weather conditions constitute the basis of Hohhot air pollution prediction.