In the light of the polyethylene oxide (PEO) structure, various polymer electrolytes based on tailor-made polyurethane (PU) were prepared and investigated by alternating current (ac) impedance. Equivalent circuits and schematic structures were proposed to describe the conductive behavior of these electrolytes. The impedance results show that water-borne polyurethane (WPU) film, impregnated with propylene carbonate (PC), has a conductivity of 2.83 x 10(-5) S cm(-1) at 80 degrees C. With the addition of salt and solvent, WPU-based electrolyte exhibits a conductivity of 4.68 x 10(-4) S cm(-1) at 25 degrees C. It is promising to use our tailor-made WPU as a polymer electrolyte for lithium batteries.