Abstract: Two kinds of typical problems frequently encountered in the control engineering were investigated, i.e. parameter uncertainty and control component failure. For a class of discrete-time uncertain interconnected systems with delays in subsystems interconnection, a linear matrix inquality(LMI)-based design methodology of decentralized robust reliable state-feedback controller was given by way of comparing the Lyapunov performance criterion of the subsystem operating normally with that of the same subsystem but suffering failure. The resulting control systems are robust and reliable in that guaranteed stability and performance were provided not onlyfor any admissible parameter perturbation, but also in case of control-channel outages. The apparently linear structure of the provided condition gives facilities for searching its numerical solution on computer and optimizing the performance specifications. Also, the relationship between reliable control and robust control of the large scale systems was analyzed with an interesting result obtained. A numerical example and the corresponding simulation was done to show the effectiveness of the proposed design method.