In an effort to predict the load-deformation response of reinforced concrete elements subjected to pure torsion, an analytical model is proposed in this study. In this model, compressive stress-strain curve and tensile stress-strain curve of concrete struts between diagonal cracks are considered in equilibrium. Experiments were then conducted to verify the validity of this model. The experimental and analytical values have been found to be in good agreement and the proposed model is thus capable of predicting not only the strength but also the angle of twist, the steel strains and the concrete strains throughout the loading history. The concrete cover and the reinforcement ratio are also found to have significant effect on the change of shear flow.