Viologen-type poly(oxytetramethylene) ionene was investigated as a matrix of polymer solid electrolyte. The ionic conductivity was evaluated by doping with LiN(SO2CF3)(2), LiClO4 or CF3SO3Li in order to elucidate the usefulness of oxytetramethylene segments and ionic units for the lithium ion conduction in the poly(oxytetramethylene) (POTM) matrix. When LiN(SO2CF3)(2) was doped to the concentration of [Li]/[-O-] = 0.125, the ionic conductivities were 1.6 x 10(-5) S/cm at 30degreesC and 8.1 x 10(-5) S/cm at 60degreesC, which were among the highest ionic conductivities of POTM-based polymer electrolytes reported so far. This solid electrolyte was thermally stable up to ca. 200degreesC. (C) 2004 Elsevier B.V. All rights reserved.