The Frictional vibration called a stick-slip occurs on the sliding surface. A familiar example of this vibration phenomenon is the chattering vibration of machine tool. When the stick-slip occurs, it leads to reduce a safety, a life expectancy and a work precision. This phenomenon has been studied for a long time, but the mechanism is not fully understood because the sliding friction behavior is caused by various factors. Therefore, it is necessary to have an analysis method that can represent the state of objects and contact surfaces. In this study, the focus was on rubber blocks, which are prone to stick-slip due to the large deformation of the object. A friction model and a deformation model in the DEM used for analysis and investigation. And, a model for analyzing the stick-slip behavior of rubber blocks is proposed. The results showed that the period and horizontal amplitude of stick-slip tended to be closer to the experimental results when the element size was reduced.