Abstract: A class of uncertain time-delay large-scale systems is studied by using decentralized model reference adaptive control where the reference model was selected according to the performance which the system expected, with the interaction between subsystems taken into account so as to keep the interconnected terms. The interconnections and disturbances in such uncertain large-scale systems are time-varying and uncertain. Under the conditions that the bounds of uncertainties are unknown though they come into being, the decentralized adaptive control law is given and it is proved that an entirely large-scale interconnected system is ultimately uniformly bounded by Lyapunov stability theory.