Abstract: Generalized modes method of defective systems foreigenvector sensitivity analysis is presented. It is proposed to establish afeature space about generalized modes by using the theory of generalizedmodes for sensitivity analysis in linear vibration defective systems whichdoes not possess a complete set of eigenvectors in N-space. Simultaneously abrief and rapid algorithm is introduced to calculate the coefficients of thepower series expression of generalized modes by gradual and recursivesolution. A numerical example is provided to illustrate the accuracy andefficiency of the algorithms.