Abstract: The motion by the inertia force of an eccentric rotor is affected by the ground friction, as is different from the theoretical results of the smooth case. If the inertia force of the rotor rotating in the counter-clockwise direction uniformly is less than the total weight of the component, the base will be in four states with the increase of the friction factor: the continuous state, the one-stop state, the two-stop vibration state and the completely static state. Due to the influence of inertia force on the normal pressure and the friction force as well, the displacement of the base to the right direction is larger than that to the left direction, when the vibration is continuous and stopping for one time. When the base of the eccentric rotor jumps up, it moves to the left just like a ``frog rammer''.