LiMnBO3 is synthesized via solid state reaction at various calcination temperatures, in order to investigate their lithium electrochemical behavior for Li-ion batteries. At lower calcination temperature, LiMnBO3 is composed of mostly monoclinic phase, with a small amount of hexagonal phase, but the ratio of hexagonal/monoclinic phase increases with an increase of calcination temperature, resulting in almost pure hexagonal phase at 800°C. Generally, monoclinic/hexagonal mixed phased LiMnBO3 displays better lithium electrochemical performance. While the pristine LiMnBO3 shows very low capacity, carbon-incorporated LiMnBO3 shows hugely improved charge-discharge capacity, in all samples. The maximum capacity, 108.2 mAh/g after 50 cycles, is obtained from LiMnBO3/C composite calcined at 600°C.