Abstract: A general method based on Riccati transfer matrix is presented to calculate the 2nd order perturbations of eigendatas for one-dimensional structural system with parameter uncertainties. The method is applicable to both real and complex eigendatas of any one-dimensional structural system. The formulas for calculating the sensitivity derivatives of eigendatas based on this method are also presented. The method is applied to the perturbation analysis for the eigendatas of a rotor with gyroscopic moment, and the differences between the perturbation results and the accurate calculating results are small.