Novel plasticized polymer electrolytes were synthesized with poly(N,N-dimethylamino-ethyl-methacrylate) (PDMAEMA), polyethylene oxide (PEO), LiTFSI as a salt, tetraethylene glycol dimethyl ether (tetraglyme), EC/PC and DEP as plasticizers. The ionic conductivity of various compositions of polymer electrolytes was investigated as a function of temperature, various concentrations of LiTFSI, plasticizers and various ratio of PDMAEMA/PEO. The ionic conductivity of PDMAEMA/PEO/LiTFSI (1.5molkg−1) with DEP as a plasticizer (1.5×10−4 Scm−1) exhibited lower than PDMAEMA/PEO/LiTFSI (1.2molkg−1)/tetraglyme (5.24×10−4 Scm−1) and PDMAEMA/PEO/LiTFSI (1.5molkg−1)/EC+PC (2.1×10−4 Scm−1). As increasing the PDMAEMA concentration up to 13.3%, the ionic conductivity was decreased rapidly. As increasing the PDMAEMA concentration the ionic conductivity was decreased due to high viscosity and some interactions reducing ion pairing. These plasticized polymer electrolytes were characterized by impedance spectroscopy and DSC.