Abstract: Concentration of various pollutants discharged at washing process was simulated using washing module of AUSTAL2000 model and pollutant source data from a thermo power station which flue gas discharged from the natural draft cooling tower.The results show that different wind speeds and cooling tower geometrical parameters exert considerable influence on the simulated concentration of pollutants in the air and at the ground.The maximum concentration of pollutant in the air and at the ground decreases along with the increasing wind speed when the height of cooling tower is 110 m.Moreover,the height of the maximum pollutant concentration in the air and the horizontal distance from the cooling tower also decrease.There is no obvious variation of the pollutant concentration in the upper air and at the ground except the maximum concentration in the air and at the ground decreasing when the height of the cooling tower increases to 130 m with other parameters unchanged.When the inner diameter of cooling tower outlet increases from 50 m to 60 m with other parameters unchanged,the pollutant concentration in the air and at the ground varies slightly with the increasing wind speed,but the horizontal distance of the maximum pollutant concentration in the air and at the ground from cooling tower increases slightly.