Thirty-three micro-environmental and one continuous sites area selected and overall 66 plus 7 samples for fine particles are collected during two seasons in Taichung city in the study. The collected samples are analyzed to obtain the mass concentration, absorption, sulfur dioxide, nitrogen oxide and metals for further statistical analysis. After time-adjusted, the two seasonal averaged value of PM2.5, PM2.5 absorbance, SO2 and NOx are 30.89 μg/m3, 21.30×10-6 m2/m3, 1.24 ppb and 24.21 ppb, respectively. Results show that lower PM2.5 and SO2 concentrations and higher PM2.5 absorbance and NOx concentration in higher floor (>4 floor) are found but all insignificant. For land use regression model building, the predictors for PM2.5 mass concentration are the floor, the inverse distance to the Taichung Coal-fired Power plant (PS2), the inverse distance to the Chenglung paper plant at Houli District (PS5), the major road area with 100-meter buffer, the livestock and other agriculture area with 300-meter buffer, the low density residential area with 1000-meter buffer, and the mine area with 1000-meter buffer with overall R2 of 0.61. In addition, the overall R2 for PM2.5 absorbance, SO2, and NOx LUR models are 0.72, 0.46, and 0.68, respectively. For source apportionment to PM2.5, time-adjusted are resolved seven principal component factors. Approximately 28.4% of PM2.5 from the mix source of power plant, high technology corporation and gasoline-powered vehicle, 1.6% from the mix source of residual oil burning and diesel-powered vehicle, 18.8 % from the mix source of sea salt and paved road dust, 10.7% from the mix source of copper/aluminum manufacture and plating plant, 6.9% from rocky acquisition and processing industry, 0.2% from steel plant, 10.6% from biomass burning, and 22.7% from undetermined source are in the model. Based on the source apportionment results by APCA method, the Taichung city government could focus on the power plant as the priority order for reducing the air pollutants. Controlling and reducing the paved road dust and vehicle emissions should be the next order. Final, the general industrial, biomass burning, and rocky acquisition and processing should be noticed to reduce the air pollutants as well as. However, the above strategies are based on limited information with metallic analyses in one year. Therefore, the Taichung city government should take care that as reference.

Central Taiwan Air Basin, Fine Particles (PM2.5), Exposure Assessment, Source Apportionment, Land Use Regression Model