Abstract: In order to find the possible causes and micro characteristics of aerosol pollution, based on the airplane detection data on Oct 19th, 2008, the aerosol distribution characteristics over Baoding and Shijiazhuang were contrasted and analyzed. The results showed that: the aerosol number concentration declined obviously under boundary layer, and approached background concentration of aerosol above boundary layer. The aerosol number concentration was accumulated near the boundary layer over Shijiazhuang, declined rapidly above the boundary layer, presented a peak value at the height of 2300 m. There were different vertical distribution characteristics near the boundary layer top. The inversion layer and relative humidity had a great impact on the vertical distribution of aerosol. The number concentration and mean diameter did not completely and positively correlate with relative humidity. The aerosol number concentration was directly related with regional emission sources below 1500 m, human activities and wind speed were important factors influencing the horizontal distribution of aerosol. The aerosol number concentration above mixed layer was mainly affected by regional transport. The aerosol particle spectrum at different height levels presented unimodal pattern over Baoding and bimodal or three-modal pattern at lower levels over Shijiazhuang.