For the large-scale interconnected systems with value bounded uncertainties existing in the state, control input and interconnected matrices, decentralized robust H∞ state feedback controller design problem was investigated. Based on the bounded real lemma the sufficient conditions for its existence were presented, three linear matrix inequality (LMI) methods i.e. direct LMI method, iterative LMI method and homotopy iterative LMI method were proposed to design decentralized robust H∞ state feedback controller. The controllers obtained have the block diagonal structure, enable the closed-loop large-scale interconnected systems robust asymptotically stable and satisfy the given H∞ performance. An example was given to validate the methods offered.