In order to study the effect of vertical ambient vibration on coupling vibration of bodyvehicleroad system, the human body was simplified as the parallel dynamic model, the vehicle was simplified as the sevenfreedom vibrating model, and the road was supposed as the Euler Beam on the Kelvin base. And then based on the interaction force between the road and the vehicle, the dynamic functions of the vehicleroad coupled system were derived. The functions were solved with the Newmark method. The riding comfort of the vehicle was appraised with the RMS of the body vibrating acceleration. The effects of the seismic wave frequency and its amplitude on the system vibration were analyzed, and the vibrating comfort of the vehicle and human physiological responses were discussed. The numeric analysis results indicate that the vertical ambient vibration aggravates the vibration of the bodyvehicleroad coupled system, and also enlarges the value of the vibrating comfort of the vehicle; the seismic wave frequency and its amplitude have great effect on the vibrating comfort of the vehicle.