Using daily data of wind speed and wind direction recorded at 14∶00 during 2006-2008 at 11 surface weather stations of the Pearl River Delta (PRD) and daily data of Regional Air Quality Index (RAQI) from 11 monitoring stations of the Hong Kong and Guangdong Pearl River Delta Air Quality Monitoring Network

the influence of wind field on air quality over the PRD were studied. Both in dry and wet seasons

the air quality of northern and eastern regions is better than that of southern and western regions of the PRD

and the air quality of central areas of the PRD is the worst. Regional transport has a great impact on the air quality of the PRD. When the regional mean wind speed (RMVS) is greater than 2.6 m/s

the air quality of the PRD is good. When RMVS is greater than 3.2 m/s

the air of PRD is very clean. When RMVS is less than 1.8 m/s

the air pollution of the PRD is serious. When RMVS is between 1.8 m/s and 2.6 m/s

the air quality of the PRD shows a complex change.