Positive active material for rechargeable lithium battery and method of preparing same

Disclosed is a positive active material for a rechargeable lithium battery. The positive active material includes a core and a surface-treatment layer on the core. The core includes at least one lithiated compound and the surface-treatment layer includes at least one coating material selected from the group consisting of coating element included-hydroxides, oxyhydroxides, oxycarbonates, hydroxycarbonates and any mixture thereof.