Abstract: Disclosed is active material for a positive electrode used in lithium secondary batteries of Formula 1 below and a method of manufacturing the active material. The active material includes large particles of 1 to 25 &mgr;m formed of a plurality of minute particles of 0.4 to 0.7 &mgr;m. The method includes the steps of adding a chelating agent to a mixture derived by dissolving lithium salt, nickel salt and cobalt salt in a solvent to a molar ratio of 0.95-1.06: 0.5-1:0-0.5; producing a gel by heating the mixture; for precursor by thermally decomposing the gel; and heat treating the precursor. LixNi1−yCoyO2  [Formula 1] where x is between 0.95 and 1.06, and y is between 0 and 0.5.