The present invention provides a cathode active material for a secondary battery and a secondary battery comprising the same, wherein a film-like coating layer including at least one lithium ion conductive compound having a band gap of 5.5-10 eV is formed on a surface of a core containing a lithium composite metal oxide at a thickness that does not cause a dielectric breakdown according to a typeof the lithium composite metal oxide and the lithium ion conductive compound under a charge/ discharge condition. Therefore, the coating layer, which surrounds a particle surface and has lithium ion conductivity, prevents electron transfer at the interface between an active material and an electrolyte to inhibit the oxidation/reduction reaction. As a result, a battery can be improved in the energydensity of the electrode and life characteristics thereof.