Based on the air pollution data and meteorological data from 2002 to 2004,the air pollution characters and trend in Zibo City were analyzed.The atmospheric environment capacity of pollutants was estimated using the A-P method.Investigation indicates that the key air pollutants are inhalable particle matter(PM10) and sulfur dioxide(SO₂),and their emissions have both exceeded the atmospheric environment capacity.In addition,the possible origins of air masses from pheripheral areas on heavy air pollution days were calculated using the NOAA HYSPLIT4 backward trajectory model,and results suggest that non-local origin pollutants were mainly transported by the northerly flow from Northeast China and eastern Inner Mongolia and the westerly flow from central Mongolia.All these findings provide a scientific basis for making plans of city’s development as well as for bring air pollution under control in the future.