Abstract: Disclosed are a polymer gel electrolyte composition, a polymer gel electrolyte prepared from the composition, and a lithium secondary battery including the electrolyte are proposed. The polymer gel electrolyte may be formed by thermal cross-linking of the polymer gel electrolyte composition including an ether-based organic solvent with excellent compatibility with a lithium metal anode, a nitrate capable of forming a stable film on an electrode surface, and an appropriate ratio of a cross-linking agent having two or more acrylate functional groups. Therefore, the polymer gel electrolyte can smoothly penetrate the anode to form an ion transport channel and improve oxidation stability through interaction between the polymer and the solvent thereof, thereby improving battery life.