Abstract: For a class of interconnected time-delay systems, a linear filter was designed for each subsystem by using the output of the subsystem as the input of the designed filter. Based on Lyapunov-Krasovskii functional method, a delay-independent sufficient condition of the existence of the linear filter was obtained. For the convenience of the filter design, a decoupling algorithm was applied to transform the obtained sufficient condition into a linear matrix inequality (LMI) which can be easily solved. Furthermore, the filter design problem was changed to a convex optimization solving problem constrained by LMI to achieve good H∞ performances. A numerical example demonstrates the feasibility of the proposed filter design method.