The new type polymer electrolyte composed of polymethyl methacrylate(PMMA) - Polyethyleneoxide(PEO) contain LiC1O₄-EC/PC and LiPF₆-EC/PC were developed for the weightless and long or life time of lithium polymer battery system with using polyaniline electrode. The gel type electrolytes were prepared by PMMA with PEO at different lithium salts in the glove box. The minimum thickness of PMMA-PEO gel electrolyte for the slim type is about <600-700㎛. These gel electrolyte showed good compatibility with lithium electrode. The test cell of Li/polymer electrolyte/polyaniline solid state cell which was prepared by different lithium salt was reaserched by electrochemical technique. Resistance of polymer electrolyte which consist of LiClO₄ is more less than that of LiPF₆ and cycle life is more longer than that of LiPF₆.