When signing for tracked vehicles, which are operated on unpaved roads or soft ground, the interaction between machine and soil must be analyzed. In this research, attention was focused on the interaction under front idler, that is, traction soil by a grouser in driving system. To verify the validity of interaction analysis between a grouser and soil by using 3D DEM soil model, traction simulations and experiments were carried out. In addition, the soil model was considered particle roughness to introduce compaction effect by compression. To check the effectiveness of the soil model, compression test and shearing test were conducted. Consequently, soil behavior and porosity change were found on the tests. And comparing the results of traction simulations and experiments, soil behavior and qualitative characteristics of traction resistance were conformed. Therefore, interaction between grouser and soil could be analyzed by using the soil model considering particle roughness.