The importance measure is employed to identify the contribution of input random variable on the vibration of aeronautic gear

and reduce the complexity involved in the optimization.The parametric model of the gear is constructed by the APDL command provided by the ANSYS.The importance measure of the lower vibration frequency is computed by the efficient SDP method with the combination of MATLAB and ANSYS.The effect of the variation coefficient on the variable importance rankings is insignificant.This research shows that it is feasible to import importance measure index into gear vibration analysis.