Abstract: This paper puts forward a newindex: the coefficientofgeneral vibrationCgv—for evaluating au- tomobiles’ride quality. Taking a Changan bus as an example, it presents the methods of determining the weighted coefficients of velocity, location, road proportion and anthropological factor,etc., which are to be used in obtaining the index ofCgv. These methods can make it more convenient and reasonable to predict the ride quality of a concept automobile.