NOVELTY - A polymer electrolyte comprises a cured product of a polymer electrolyte forming composition. The composition comprises a polymer of polyethylene glycol di(meth)acrylate compound (I) and/or multi-functional ethyleneoxide compound (II); one monomer chosen from vinylacetate monomer (III) and/or (meth)acrylate monomer (IV); and an electrolytic solution comprising lithium salt and an organic solvent.    USE - For lithium battery (claimed).    ADVANTAGE - The polymer electrolyte has good ionic conductivity at room temperature and good mechanical properties. Lithium battery produced using the polymer electrolyte, has improved processability, high rate discharging characteristics and low temperature discharging characteristics.    DETAILED DESCRIPTION - A polymer electrolyte comprises a cured product of a polymer electrolyte forming composition. The composition comprises a polymer of polyethylene glycol di(meth)acrylate compound of formula (I) and/or multi-functional ethyleneoxide compound of formula (II); one monomer chosen from vinylacetate monomer of formula (III) and/or (meth)acrylate monomer of formula (IV); and an electrolytic solution comprising a lithium salt and an organic solvent.    R1, R2, R3 = H or CH3;    n = 1-100000;    R4 = 1-20C alkyl; and    a+b = 6.    INDEPENDENT CLAIMS are included for the following:    (1) a method of preparing the polymer electrolyte, involves preparing the polymer electrolyte forming composition, casting the prepared polymer electrolyte forming composition and curing the cast polymer electrolyte composition by heat or ultraviolet radiation;    (2) a lithium battery comprising a cathode (3), an anode (4) and the polymer electrolyte interposed between the cathode and the anode; and    (3) a method of preparing the lithium battery, involves obtaining the polymer electrolyte, interposing the obtained polymer electrolyte between the cathode and the anode to form an electrode assembly, placing the electrode assembly into a case (1), injecting one electrolytic solution or another electrolytic solution into the case to form the lithium battery, and thermally treating the formed lithium battery to perform a polymerization reaction in the lithium battery.    DESCRIPTION OF DRAWING(S) - The figure shows the lithium battery.    case (1)    separator (2)    cathode (3)    anode (4)