Disclosed herein is an electrolyte for lithium secondary batteries comprising: a chelating agent, which forms complexes with transition metal ions in the battery, and at the same time does not react and coordinate with lithium ions; a non-aqueous solvent; and an electrolyte salt, as well as a lithium secondary battery comprising the electrolyte. The chelating agent, which is contained in the electrolyte for lithium secondary batteries, can suppress a side reaction in which transition metal ions are reduced and deposited as transition metals on the anode. Also, the chelating agent can suppress internal short-circuits in the battery and the resulting voltage drop of the battery and a reduction in the safety and performance of the battery, which can occur when transition metals are deposited on the anode.