The present invention relates to a composition for a gel polymer electrolyte, which includes an oligomer represented by Formula 1, an anion stabilizing additive, a polymerization initiator, a lithium salt, and a non-aqueous solvent, wherein the anion stabilizing additive includes at least one selected from the group consisting of a phosphite-based compound represented by Formula 2 and a boron-based compound represented by Formula 3, and a gel polymer electrolyte and a lithium secondary battery which are prepared by using the same.