Abstract: By nowadays, the application of straw returning technology has been implemented continuously for years in China, as a result, that the content of immature straw in soil has increased obviously. For the contact system of tire/tool-soil, the interacted relationship of them is influenced by the environmental changing of soil. In this paper, a tri-axial shear test for the soils with different rice straw contents has been carried out. The condition of the soil was changed with different quantities of rice straw, such as none of the straw contented, 40 grams straw mixed in, and 140 grams straw mixed in. In terms of the experimental result, the frictional angle, the adhesive strength, and the bulk density of the soil were all decrease with the increase of straw content. According to this research, the shearing performance of the rice straw contented soil also showed a downward trend under the same grounding pressure when the straw content of the soil was increased.