Road noise, excited by road roughness, is one of the NVH (Noise, Vibration and Harshness). Tires greatly influence the level of NVH experienced in the vehicle. Thus, tire vibration characteristics impact the spectra of road noise. This paper describes our research of tire dynamics using low DOF model. First, we built tire dynamics model based on thin cylindrical shell theory. This model can express all modes below 200Hz. Second, we performed vibration analysis on the contact and rolling condition and clear up the vibration characteristics analytically.