Abstract: In the previous study on additional stress in soil of ground always, soil is apt to be assumed as an elastic continuous medium. In fact, since soil is a solid-liquid-gas three-phase incompact system and the structure of soil is a complex system formed by several levels, it is greatly different from elastic continuous medium. To represent regularity of additional stress more correctly, the mesoscopic structure model of additional stress transfer in the soil is proposed to study its mechanics in this paper. This model also explains concentration and diffusion of additional stress in layered ground.