In this work, novel alkaline solid polymer electrolytes (SPEs) with tetramethyl ammonium hydroxide (Me4NOH·xH2O) have been developed, without addition of any volatile solvent. It was found that some polymers such as poly(sodium acrylate) had good compatibility with Me4NOH·xH2O. The polymer-Me4NOH·xH2O electrolytes thus prepared in this work appeared to have improved mechanical properties as compared with the pure hydroxide and remained highly conductive in the solid state (102 S cm−1 at ∼40°C). The thermal properties of the alkaline SPEs and the dependence of conductivity on composition and temperature are presented, and the relationships between properties and composition as well as conductivity mechanism for these new systems are discussed.