In this paper, an input decentralized control strategy is used to decompose MIMO system into many SISO subsystems. Placing the desired pole locations at a predetermined value by ITAE for each subsystem may lead to slow overall system eigenvalues because of the interactions among each interconnected subsystem and others. Linear quadratic optimal technique is applied over subsystem level in order to shift the slowest obtained pole locations into much more stable places, which in turn shift the slowest overall system eigenvalues and guarantee a higher stability degree. This procedure is repeated many times until all the desired poles are achieved.