The paper studies the decentralized robust stabilization problem for a large-scale system which is composed of three subsystems. Each subsystem may contain nonlinear and/or time-varying uncertainties and interconnections; but one of these subsystems does not have direct control. We demonstrate a control design procedure where the interconnection characteristic is fully utilized. By showing that it is possible to use the interconnection as a bridge to convey the influence of control, decentralized controls can be designed.