Abstract: The long-term concentration is calculated using the general second-order moments Guassian puff model and the high-resolution wind fields from Guangzhou tropical model (GZTM).The Guassian puff model includes the processes of the puff's splitting-merging and scavenging. The ppollutant synthesised index of Pearl River Delta cities is predicted with the fellowingstepe. The first is to have the SO₂,NO_x,TSP's ground concentrations simulated and the drilyaveraging concentration of every kind of species gained. The second is for the pollutant index P_i ofevery kind of species to be calculated to compare with the second respective division of pollutionstandards. The last is to compute pollutant synthesised index P computed with adding each P_i.