To study the ride comfort of the long span bridge, five tests of vibration for vehicle passing the bridge in different condition were conducted. The effect of the dynamic characters of the vehicle and the bridge, the roughness of the deck and the vehicle speed on the vibration inside vehicle was investigated by analyzing measured vibration data. A time frequency domain method based on wavelet transform was used to extract the energy distribution of vibration inside the vehicle The results show that the dynamic characters of the vehicle have more influence on vertical vibration inside the vehicle. However the dynamic characters of the bridge deck have more influence on lateral vibration inside the vehicle. The vibration amplitude is mainly determined by the roughness and the expansion joint and increase with the vehicle speed. The lateral vibration of the vehicle passing the Cross Sea Bridge has a rapid increase as the vehicle speed exceed 80km/h. The research results have important reference value in evaluating ride vibration comfort of long-span Bridge.