To provide a vehicle vibration analysis method and its device for grasping components having to be improved as to the vibration transmitting characteristics of a vehicle.

In executing vibration analysis on the vehicle, firstly, its wheels are vibrated by a four-wheel vibration tester with the respective wheels of the vehicle mounted on a vibration table of the vibration tester. Subsequently, the suspension characteristics (the transfer functions of suspension-transmitted force/tread displacement) of the vehicle, the body characteristics (the transfer functions of body acceleration/suspension-transmitted force) thereof, and the seat characteristics (the transfer functions of seat acceleration/body acceleration) thereof are calculated based on measurement values of a displacement meter provided on the vibration tester and those of an accelerometer provided on the vehicle. Subsequently, the level of vibration of the vehicle corresponding to actual road travel is calculated based on the body characteristics, the seat characteristics, and road surface information on actual roads, to output results thereof.