An electrode active material further comprising an amphoteric compound, an alkali metal sulfide or an alkali metal oxide, and lithium secondary batteries using the electrode active material, are disclosed. The lithium secondary batteries neutralize acids generating around electrode active material so that it can inhibit the reduction in battery capacity. In addition, the lithium secondary batteries are excellent in its charge-discharge characteristics, cycle life and thermal stability. A method for preparing the electrode active material for lithium secondary batteries is also provided.