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The sampling was conducted simultaneously in August 2006 at the levels of 10，120，220 m of the 255 m meteorological tower in Tianjin with the Andersen cascade sampler. The atmospheric aerosol samples are analyzed by IC (Ion Chromatograph) and ICP/MS (Inductively Coupled Plasma Mass Spectrometer). The results indicate that there are three types of size distribution: (1) K particles are mainly in the fine particle section with the peak at 0.43 to 2.1 μm. (2) Mg, Ca, Al, Fe are mainly in the coarse particle section with the peak at 2.1 to 9.0 μm. (3) Na particle distribution exhibits a doublepeak structure with the peaks at 0.65 to 2.1 μm and 3.3 to 5.8 μm. SO2-4, NO-3,NH+4 and Ca2+ are mainly watersoluble ions，which occupy 17.6%，45.7%，18.1% and 13.7% in the total ions，respectively．The total concentration of ion, as well as NO-,3 SO2-4 and NH+4, increases with height. The ion balance values between total cations and total anions at various levels are less than one, which indicates that the aerosol is slightly alkaline, can attributed to the soil properties of Tianjin. The mean concentration ratio of NO-3 to SO2-4 is 0.48，indicating that coal burning，which represents the stationary sources, compared to the mobile sources of vehicle emission，is the main pollution sources of watersoluble ions in Tianjin．