Abstract: Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ Li-rich layered cathode material was prepared by one-step oxalate method. The composition, structure and electrochemical properties of the material were characterized and analyzed with X-ray diffraction, inductively coupled plasma torch (ICP) emission spectrometry, field emission scanning electron microscopy, transmission electron microscopy and method of electrochemical analysis. The results show that the prepared sample is irregular rod with a length of 2-5 mm and a diameters about 200 nm, and it exhibits accurate stoichiometry, higher crystallinity and low degree of cation mixing in Li-layers. The obtained cathode material delivers a discharge capacity of 242.4 mA·h·g^-1 at a current density of 20 mA/g, showing a high initial Coulombic efficiency of 74.9%. And at current density of 1 000 mA/g, it still possesses a high capacity of 98.8 mA·h·g^-1. After cycled for 100 cycles at 200 mA/g, it exhibits high capacity retention of 76.8%.