Herein, the role of friction-induced torque in sliding friction of rubber materials is investigated. A friction tester was developed to monitor the friction force between a silicon rubber block and a surface made of PMMA(1). Based on the experimental results, a simplified model was developed to express the nonuniform distribution of normal pressure developed due to the friction-induced torque, and the normal pressure dependence of the real contact area based on Persson's contact theory. Based on the modeling, the mechanism of the effect of the friction-induced torque on frictional force reductions was clarified. (C) 2015 Elsevier Ltd. All rights reserved.