We investigated the average, local and electronic structures of LiMn_1/3Ni_1/3Co_1/3O₂ prepared by various methods. Their electrode characteristics were also studied by charge-discharge test. As a result, it was demonstrated that the sample synthesized by solution method exhibited the most excellent cycle performance. In order to clarify how the preparation processes affected on the crystal structures in detail, local structure, i.e. cation mixing and transition-metal ordering, in the samples were analyzed by Pair Distribution Function (PDF) method using a neutron source and X-ray absorption fine structure measurements. From this analysis, it was found that the local structure in LiMn_1/3Ni_1/3Co_1/3O₂ depended on the preparation process. Such a difference in the local structures may result in different cathode properties among the samples synthesized.