The problem of eigenstructure assignment in multivariable linear systems by decentralizde output feedback is considered. By using a complete parametric solution of a generalized Sylvester matrix equa-tion, parametric reprssentations of both the left and right closed-loop elgenvectors and generalized eigenvectors as well as the feedback gaino with respect to the closed-loop eigenvalues and two series of partially free parameter vector are established. The obtained result does not require any conditions on the closed-loop eigenvalues, and generalize some previous results in thi area. An example shows the effect of the proposed approach.