This paper considers a class of uncertain generalized large-scale composite system and studies the decentralized stabilization problem for the system by employing Lyapunov method and using the matrix norm properties. We design a kind of decentralized output feedback robust controllers and obtain the norm bounds of system uncertainties which ensure robust stabilization for the system. Meanwhile, we　analyse the impulse control problem of uncertain generalized composite system and its isolated subsystems. We give the norm bounds of system uncertainties which ensure the closed loop system impulse free. Finally, we obtain the norm bounds of being asymptoticly stable and impulse free for the closed loop of uncertain generalized composite system and its isolated subsystems.