Abstract: The particle samples from the cement kilns and coal-fired boilers in Chongqing city were collected by using a flue-gas cascade dilution sampler. The samples were then classified into 12 levels by an electric low pressure impactor (ELPI), and the size distribution characteristic of particles (0.02~10 μm) from industrial sources analyzed. The results showed that the cement kiln exhibited double-peak type logarithmic distribution, with the peak respectively at the accumulation status (0.12 μm) and the near-coarse particle status (1.23-1.96 μm), while the particle number concentration of coal boilers source presented one single peak of accumulation status. The particle-number concentration and mass concentration of the large power plant were higher than other sources, with the peak value being 2.2×106 cm^-3, and 174.2 mg/m³, respectively. The OC, Al, and Ca were relatively high in the cement kiln PM_2.5, accounting for 17.96%, 17.32% and 9.90% of PM_2.5, respectively, while Al, SO₄^2-, and OC were relatively high in the coal-fired boiler PM_2.5, accounting for 9.17%, 8.92% and 6.15%, respectively. Compared with carbonaceous and water-soluble fractions, the inorganic fraction contributed more to PM_2.5 in the industrial sources, responsible for 44.28% in the cement kiln sources and 18.07% in the coal-fired boilers sources.