Air sparging is an accepted technology for remediation of soils contaminated with volatile organic compounds (VOCs). The micro-mechanics of air sparging is helpful in understanding the mechanism behind air migration and the spatial distribution of air phase during air sparging. In order to conduct microscopic research on air sparging, a 3D network which can capture both the geometrical information of soil matrix including pore size and throat size distributions with their correlation and the topological information of soil matrix including the distribution of coordination numbers was proposed. A complete procedure of developing the 3D microscopic network model was developed and presented. The method of estimating or acquiring the geometrical and topological information of soil structure was also presented. Finally, the validity of the developed network was verified by capturing the main structure properties of the soil matrix. The simulation confirmed that the proposed model can be used to investigate micro-mechanics of air sparging.