A polymer electrolyte has improved leakage resistance and a lithium battery uses the polymer electrolyte. The polymer electrolyte includes a polymerization product of a polymer electrolyte forming composition that includes a multi-functional acrylate based compound, at least one selected from the group consisting of polyalkylene glycol di(meth)acrylates and polyalkylene glycol (meth)acrylates, and an electrolytic solution containing a lithium salt and an organic solvent.