Estimate of population exposure to air pollution is necessary to health impact assessment. Based on the concept of intake fraction, a rapid population exposure assessment method was developed in this paper. The CALPUFF atmospheric dispersion model was applied to estimate intake fractions of primary and secondary fine particles emitted from a set of 17 power plants in Hunan Province. Results showed that within 500 km from the emission source, average values of intake fraction were 9.73 x 10(-6) for PM2.5, 2.39 x 10(-6) for sulfate and 2.47 x 10(-6) for nitrate. From regression analysis, good correlations were found for the relations among intake fraction of PM2.5, stack height, and population (R2 = 0.83), and intake fraction of SO(4)2- and population (R2 = 0.64), and intake fraction of NO3-, stack height and population (R2 = 0.74). Iso-intake fraction maps were produced based on the regression equations and population distribution, which reflected the differentiation of population density and enabled simple impact assessment for emission sources in this region.