Abstract: A series of nanocrystalline lithium-rich cathode materials (Li1.2Ni0.2Mn0.6O2) have been prepared via an ultrasonic/microwave-assisted co-precipitation method. The effects of the ultrasonic time are emphasis investigated by using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements. The optimum reaction time is 2h, while the sample can exhibit the best electrochemical properties with an initial discharge capacity of 265mAh.g-1 at 0.1C and 180mAh-1 at 2C after 90 cycles, respectively. The superior electrochemical performance of this material can be attributed to the uniform particles, desired element distribution and high activities of the redox couples in the bulk material. This study also suggests that the ultrasonic/microwave system can be a good assistant in the practical Li-rich material production, while it can be easy to use and time-saving.