【Objective】The characteristics of soil hydraulic conductivity are used to construct the geometric model of pore parameters, but the variation of hydraulic parameters in field is usually very large and the measurement efficiency is low. Soil air transmission is highly dependent on soil pore structure and acquisition of the air permeability is simple, fast, and efficient, and little damage to soil structure.Using soil air permeability rate to analyze soil structure and pore geometry distribution is becoming the focus of attention.【Method】We use soil air permeability measurement instrument (PL-300) to get the air permeability, and use the centrifuge to get the soil water characteristic curve.We measured the air permeability of undisturbed and disturbed soils under different water contents and different soil bulks, through the two relative air permeability curve fitting bending pore connectivity factor, we discussed the pore structure and pore tortuosity-connectivity.【Result】The results showed that: 1) Pore tortuosity-connectivity increased with air phase saturation increasing，and the increase degree of undisturbed soil is more significant than disturbed soil. When the air saturation is 18%, 32%, 60% and 86% , the relative permeability of the disturbed soil is respectively 50.77%, 51.65%, 50.31%, and 51.02% of the undisturbed soil. The trend curves of relative air permeability and saturation, both of undisturbed and disturbed soil, were basic same, but not coincident. Which means that the degrees of pore tortuosity-connectivity is different, even if the saturation of undisturbed soil and disturbed soil are same. 2) The air permeability of undisturbed soil depended on the existence of macroporosity, while the air permeability of disturbed soil not only depended on the degree of pore connectivity, but also depended on pore tortuosity-connectivity.【Conclusion】Based on the discussion which soil air permeability create the change of soil pore structure make for pore geometry feature differences, in the soil air transmission and pore structure of the related research and the process of application in mathematical model, in addition to the analysis of soil physical basic parameters, should be taken into account the influence of pore size distribution on air permeability under the condition of high moisture content, distinguishing and discussing undisturbed and disturbed soil different bending connectivity factor, in order to further reveal the internal mechanism of soil air transmission to provide the reference.