The present invention provided a positive electrode active material for a lithium secondary battery including lithium cobalt oxide particles. The lithium cobalt oxide particles include lithium deficient lithium cobalt oxide having Li/Co molar ratio of less than 1, belongs to an Fd-3m space group, and having a cubic crystal structure, in surface of the particle and in a region corresponding to a distance from 0% to less than 100% from the surface of the particle relative to a distance (r) from the surface to the center of the particle. In the positive electrode active material for a lithium secondary battery according to the present invention, the intercalation and deintercalation of lithium at the surface of a particle may be easy, and the output property and rate characteristic may be improved when applied to a battery.