LiMnBO3/carbon composite cathode material has been synthesized by using a ball-milling and. postannealing method. The LiMnBO3/C sample was characterized by using XRD, SEM, TEM, and electrochemical tests. The XRD results reveal the formation of a phase with the hexagonal structure. The SEM and TEM images indicate that the LiMnBO3 particles are approximately 100 nm in diameter and are embedded in a porous carbon matrix. The electrochemical measurement results indicate that the LiMnBO3/C cathode exhibits excellent electrochemical performance, deliver a high discharge capacity of 209.3 mA h g(-1) at 0.025 C, and possess favorable capacity at the rates of 0.05, 0.1, 0.2, and 1 C in the voltage range 1.0-4.8V.