For a class of value-bounded uncertain descriptor large-scale interconnected systems, the decentralized robust H∞ descriptor output feedback control problem is investigated. A design method based on the bounded real lemma is developed for a decentralized descriptor dynamic output feedback controller, which is reduced to a feasibility problem for a nonlinear matrix inequality (NLMI). It is proposed to solve the NLMI iteratively by the idea of homotopy, where some of the variables are fixed altately at each iteration to reduce the NLMI to a linear matrix inequality (LMI). A given example shows the efficiency of this method