Cable parameter identification in a cable structure is very critical in both construction and maintenance of the structure. A new parameter identification method is presented, and it can accurately identify the cable parameters, such as cable tension and flexural stiffness based on finite element model (FEM) and system identification technology. Considering the effects of sagging, flexural stiffness, tension, boundary conditions, and flexibility support, three-node-beam-element FEM is formed to study nonlinear vibration of cables. An eigen value sensitivity matrix is obtained from the first -order Taylor series expansion of the non-dimensional eigenvalues with respect to the parameters to be identified. The equations relating the parameters identified to the differences between the analytical and the measured frequencies are established. The parameters can be determined accurately through the proposed equations in a new iterative fashion. The precision of the identified parameters and the convergence are enhanced. The numerical and experimental study is conducted to verify the identification method.