This paper is concerned with a pragmatic and graph-theoretical approach to decomposition and control of large-scale linear systems. Topological matrix belonging to the state-variables of the system is utilized for the decomposition of the system into its sub-systems in a hierarchically ordered manner. Decentralized control design is then followed for a selected subset of the subsystems having outputs requiring immediate or fast control action. This is followed by the design of decentralizing feedback for the second subset of the system components including the closed loop control system of the first level. Various alternative design considerations are discussed.