A polymer electrolyte composition for improving overcharge safety and a lithium battery using the same are provided. The polymer electrolyte composition includes acrylate, epoxy or isocyanate at both of its terminals, and includes a compound containing an aromatic group such as thiophene, biphenyl or furan in an amount of 0.1% to 20% by weight based on the amount of the overall organic electrolytic solution. The polymer electrolyte composition further includes at least one of polyethylene glycol diacrylate (PEGDA), polyethylene glycol dimethacrylate (PEGDMA), and a mixture thereof. A lithium polymer battery using the polymer electrolyte composition can be suppressed from danger of ignition or explosion when the battery is overcharged due to some uncontrolled conditions, such as failure of a charger. Moreover, an additional cutoff device is not necessary, while still exhibiting good life cycle characteristics of the battery.