This article topic comes from an automobile company. As part of a passenger car vibration and noise reduction , the study was carried .The study content of this article is relate vehicle road test ,build FEM model of passenger cars body, body calculating modal analysis ,morphology optimization and so on . In this paper, based a passenger car, the study was carried out .Firstly the road test was carried base on the national standard GB/718697-2002. The acceleration signal of key part was tasted at the idle a...