The high voltage cathode material, LiMnPO4, has gained a lot of attention, because of its properties of non-toxicity, high voltage, excellent cycle performance and security. But the shortages of this material limit its application, such as the bad electronic conductivity, intrinsic conductivity and rate capability. In recent years, the electrochemical performance of LiMnPO4 has been improved significantly by increasing the electronic conductivity between the particles, the intrinsic conductivity of particles and decreasing the size of particles. In this paper, we mainly introduced the structure and properties of LiMnPO4 and the methods of synthesizing and improving LiMnPO4 material, including high temperature solid-phase, sol-gel, hydrothermal method and spray drying, surface coating, doping and nano-structure synthesis. We also concluded the current situation and the problems of the research of LiMnPO4 material and gave some comments of the main research direction