The finite element solution of fluid/structure interaction problems is considered for a class of acousto-elastic problems where the fluid is linear acoustic and the structure is linear elastic. The finite element formulation in terms of fluid pressure and structural displacement results in a system of unsymmetric equations. Due to the complexities of eigensolution for large systems involving unsymmetric matrices, little progress has been reported. Recently, Yu showed that the real form of QZ algorithm can be used for solving small unsymmetric eigenproblems of fluid/structure interaction, and, as a major advance, now presents the use of the subspace iteration method, in conjunction with the QZ algorithm, for solving large fluid/structure systems. The computational procedure is similar to that for the real symmetric case, and the procedure can easily be adopted by any finite element code.