A series of novel polyurethane ionomers with polydioxolane (PDXL) as soft segment was prepared and characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and dynamic mechanical analysis. The ionomers obtained were Na+ single-ionic conductors. Their ionic conductivity and water absorption were tested. At medium temperature (> 75 degrees C), the conductivity of similar to 10(-5) s cm(-l) was reached. The temperature dependence of conductivity could not be well expressed by both Arrhenius and VTF equations. When ionization level was fixed, the conductivity increased as the Mn of PDXL decreased. We also discussed the effect of ionization level on water absorption.