Consideration was given to tracking the given trajectories of the output variables of the linear multiple-input multiple-output system under uncontrollable external smooth disturbances. A step-by-step transformation pro-cedure of initial system to joint block-canonical form of controllability and observability with respect to the output variables with regard for the external disturbances was presented. This form underlies the decomposition procedures of feedback design enabling one to track the given trajectories invariantly to the external distur-bances.