Abstract: Based on the reduced-order finite element(FE) model and its Monte Carlo-response surface method,the localization characteristics of a typical bladed disk with geometry mistuning were researched in detail,with particular regard to the subjects of the probability characteristics for the forced response.An FE modeling method of bladed disks with geometry mistuning was given,and the order-reduction method was presented as well.Then the response properties of the tuned structure were discussed.The response magnification factor was defined to assess quantitatively the behavior of the vibratory localization.The statistical characteristics of the forced response of the stochastically mistuned and detuned structures were simulated and their main properties were explained.Results indicate that there is a peak phenomenon in the mean values and standard deviations of the response with the increasing mistuning strength.