Abstract: A method for calculating the natural property of assembling shroud blades is presented. By replacing assembling shroud blades with system of thin plates and springs, a series of differential equations concerning dual interaction between blades are established and transformed by mode coordinates, and the unknown stiffness of spring (acting stiffness of shroud) could be obtained experimentally. Furthermore, natural frequencies and corresponding modes of the system are acquired by solving the eigenvalue problem of the set of the equations. The results show that the proposed approach can deal well with the problem on the inherent property of assembling shroud blades.