Disclosed is a positive active material for a rechargeable lithium battery. The positive active material includes at least one compound represented by formulas 1 to 4:

where M is selected from the group consisting of Co, Mg, Fe, Sr, Ti, B, Si, Ga, Al, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No and Lr, 0.95x1.1, 0y0.99, 0z0.5, and 0a0.5; and a metal oxide or composite metal oxide layer formed on the compound.