FTIR and ESR studies of sulfonated EPDM ionomers in xylene/alcohol show that alcohol solvation of - SO(3)M occurs and the extent of solvation relates to the species and concentration of the metallic ions and the molar concentration of - OH from the cosolvent (alcohol) and temperature. The relationship between these factors and the viscometric behaviors of the ionomer solution were investigated. The results of these two studies are quite consistent with each other. At the molecular level the solvation of the metallic ion with the cosolvent plays a key role in the anomalous viscosity-temperature behavior of ionomer solutions.