Based on the statistical data of the auto-monitoring air quality stations of EPA in Tainan city (Tainan and Annan), it was found the days with PSI more than100 of both stations were mostly caused by the PM10. The percentage of PM10 to be the predominant pollutants was 71%. Under the instruction of air quality improvement project established by the EPA, Taiwan, the Environmental Protection Bureau of Tainan city conducted the plan entitled ‘Intensification of street washing and sweeping for the removal of the wind-borne dust in Tainan’. This work set priority to wash and sweep the streets located at places around the air quality stations, with high population density and heavy traffic flow. Hopefully, the air quality of Tainan city could be improved through the implementation of this project.