The automobile gearbox is a muti-DOF elastic vibration system.The each kind of load which affects the gearbox system can be cause the complex vibration of gearbox.it inevitably brings the vibration and the noise of the automobile and affects the automobile ride comfortableness.The three dimensional solid model of gearbox of the ALTO car is established based on the Solidworks

and the FEM model for dynamic analysis of the gearbox in the COSMOSWorks.The result can be to provide a theory basis for finding out the sensitive part of the gearbox vibration and structural design of the box body.