Conclusions HYPACT/RAMS modeling system was applied to simulate PM10 dispersion at MPIA in Saraburi during the PM10 episodes 2005. The simulated PM10 concentrations are generally in good agreement with the observations. The information of the model results is useful for air quality management. The model results reveal the dispersion of PM10 emitted from significant sources in Nah Phra Laan and its vicinities. It is found that PM10 emitted from this area impact mainly on local area. The high PM10 concentrations appear near sources that can be explained by a large number of coarse particles and low atmospheric ventilation conditions. Model results show the highest concentration areas that are different locations between winter and rainy season. In winter episodes, it appears about 5 km southwest from the monitoring station. While in rainy season episodes, it appears around Nah Phra Laan center. These areas should be monitored and studied impact of particulate pollution.