Provided are a lithium secondary battery electrolyte and a lithium secondary battery. The lithium secondary battery electrolyte includes a lithium salt, a non-aqueous organic solvent, and a pyrrole derivative. The lithium secondary battery includes a cathode, an anode, a separator, and the lithium secondary battery electrolyte. The secondary battery electrolyte according to the present invention has advantages of excellent stability at a high temperature and high discharge capacity at a low temperature.