The paper is concerned with the decentralized constant control of a. multimachin power system through the eigenstructure assignment approach. Adopting decentralized control, would lower the cost and increase the reliability of the proposed scheme under any variation in the system structure. Having an eigenstructure assignment approach, means determination of the proper feedback gains that realize an apriori set of eigenvalues and eigenvectors. The eigenvalues would determine directly the rate of change of any perturbation while eigenvectors would reshape that change in a Hay that can be accepted practically. Since the interaction between machines has an effect on the overall damping of the system, the modification of the proposed closed-loop eigenvalues to enhance that damping is shown.