NOVELTY - An electrolyte of lithium secondary battery (100) comprises a non-aqueous organic solvent, a lithium salt soluble in the non-aqueous organic solvent and ortho-terphenyl.    USE - electrolyte of lithium secondary battery is used for wireless devices such as video camera, cellular telephone and transportable computers.    ADVANTAGE - The electrolyte of lithium secondary battery has improved capacity, cyclic characteristics and durability, and reduces the impedance at interface between cathode active material layer and electrolyte and provides stable discharge even at low temperature.    DETAILED DESCRIPTION - An electrolyte of lithium secondary battery comprises lithium salt in non-aqueous organic solvent, and ortho-terphenyls. The electrolyte further includes biphenyl and cyclohexyl-benzene. The non-aqueous organic solvent includes carbonate, ester and ketone. The organic solvent is mixed solvent of cyclic carbonate and chain carbonate. The chain carbonate solvents are chosen from dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl methyl carbonate or ethyl propyl carbonate. The cyclic carbonate is chosen from ethylene carbonate, polypropylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate or 2,3-pentylene carbonate. The non-aqueous organic solvent is a mixed solvent of aromatic hydrocarbon based organic solvent and carbonate solvent. The aromatic hydrocarbon based organic solvent is chosen from benzene, fluorobenzene, chlorobenzene, bromobenzene, toluene, xylene or mesitylene. The lithium salt is chosen from Lithium Hexafluorophosphate, Lithium Tetrafluoroborate, lithium antimony-fluoride, lithium hexafluoroarsenate, lithium perchlorate, lithium trifluoro-methane sulfonate, Lithium bis (trifluoro methylsulfonyl) imide, Lithium bis (pentafluoro ethylsulfonyl) imide, lithium tetrachloroaluminate and other lithium compounds (LiC(SO2CF3)3, LiC4F9SO3 and LiN(SO3CF3)2), lithium aluminum compound (LiAlO4), lithium chloride or lithium iodide. The lithium secondary battery further comprises anodic active material containing lithium compound chosen from LixMn1MnyMyA2, LixMn1MnyMyO2MyOzXz, LixMn2O4OzXz, LixMn2MnyMyM'zA4, LixCo1CoyMyA2, LixCo1CoyMyO2OzXz, LixNi1NiyMyA2, LixNi1NiyMyO2OzXz, LixNi1NiyCoyO2OzXz, LixNilNizCoyMzA~a, LixNi1NizCoyMzO2OX~a, LixNi1NizMnyMzO2OX~a or LixNi1NizMnyMzA~a where x is 0.9-1.1, y is 0-0.5, alpha is 0-2, M and M'are chosen from magnesium, aluminum, cobalt, potassium, sodium, calcium, titanium, silicon, tin, vanadium, germanium, gallium, boron, arsenic, zirconium, manganese, chromium, iron or strontium and rare earth elements, A is chosen from oxygen, fluorine, sulfur and phosphorus, and X is chosen from fluorine, sulfur and phosphorus. The anode active material is chosen from carbon amorphous carbon, carbon complex, carbon fiber, lithium metal and lithium alloy.    DESCRIPTION OF DRAWING(S) - The drawing shows cross sectional view of lithium secondary battery.    Lithium secondary battery (100)    Electrode assembly (105)    Anode plate (110)    Separator (130)    Cap assembly (160)