An electrolyte for a lithium secondary battery is provided. The electrolyte includes a lithium salt, a non-aqueous organic solvent, and a compound represented by Formula (1): ##STR1##

wherein R₁, R₂, and R₃ are each independently selected from the group consisting of hydrogen, primary, secondary, and tertiary alkyl groups, alkenyl groups, and aryl groups. The compound of the present invention is decomposed earlier than an electrolytic organic solvent, and an organic SEI film is formed on a negative electrode, thereby inhibiting the electrolytic organic solvent from decomposing.