Abstract: The global exponential stability of a class of linear interconnected large-scale systemswith time delayswas analyzed based onM-matrix theory and by constructing a vectorLyapunov function. A criterion was obtained for global exponential stability of the systems by analyzing the stability of differential inequalitieswith time delays under the assumption that the time delays are bounded and continuous. A large-scale system is global exponential stable if the testmatrix is anM-matrix, where the testmatrix is constructed by employing the coefficientmatricesof the system and the solutionsof the Lyapunov equationswhich are interconnectedwith the system. Since it is independentof the delays and simplifies the calculation, the criterion is easy for application.