An electrolyte for an electrochemical nitrogen reduction reaction and a method for electrochemically preparing ammonia using the same are provided. The electrolyte includes a first lithium salt including at least one selected from the group consisting of a fluoroborate-based lithium salt, a fluorophosphate-based lithium salt, a fluoroarcenate-based lithium salt, and a fluorosulfonylimide-based lithium salt, a second lithium salt different from the first lithium salt, and an organic solvent.