Spinel phase LiMn2O4 is of great interest as cathode materials for lithium-ion batteries. We describe here a new simplified technique (Combustion method) to synthesize LiMn2O4 directly from lithium nitrate, manganese nitrate and urea. The influence of the Li/Mn ratio of product, the mole ratio of urea to nitrate, the preset temperature of the furnace and the heat-treated time have been explored. The resultant LiMn2O4 synthesized under the optimum synthesis conditions shows perfect spinel structure, uniform particle size distribution and excellent electrochemical performances.