Abstract: The problem of asymptoticaly tracking vector-valued step reference signal and static decoupling for MIMO system is discussed,applying the internal stability controller parametrization of closed-loop system and internal principle of eliminating system error. By selecting the free parameter matrix of the controller, and making the the internal assignment to reference signal,asymptotic tracking and static decoupling is realized.Finally,an example is given to illustrate the effectiveness of the proposed method.