The present invention relates to a negative active material for a lithium rechargeable battery and a method of preparing the same, and the negative active material prepared by coating a carbon source with a coating liquid, and drying the carbon source, and the negative active material comprises a core having a carbon source with surface-treatment layer formed on the surface of the core, the surface-treatment layer having at least one compound of coating element selected from the group cosnsisting of amorphous, semi crystalline, or crystalline hydroxides, oxyhydroxides, oxycarbonates, and hyd roxidecarbonates.The present invention provides a negative active material coated with a surface-treatment layer of a coating-element-included hydroxide, a coating-element-included oxyhydroxide, a coating-element-included oxycarbonate, or a coating-element-included hydroxycarbonate, and thereby a battery having the negative active material has less change in thickness after expansion of the active material, that is, from 12.2% to 5.3%, and furthermore, cycle-life characteristics are improved (7% or more improvement at the 200th cycle) and voltage characteristics are improved (0.04 V or more improvement at the 200th cycle).