Lithium iron phosphate with the structure of olivine has many advantages: low price, environmentally friendly, great thermal stability and excellent cycle performance when used as the anode materials, making it one of the most promising anode materials. In this article, we used the precusor FePO4 pre-prepared to produce LiFePO4 and the performances were tested. The process of preparation of the precusor FePO4 were optimized and the reaction mechanism was probed into. The precusor FePO4 was prepared by the raw materials as follows: ferric nitrate, phosphoric acid and diammonium hydrogen phosphate, the temperature, PH, Fe/P and the time of reaction were considered. LiFePO4 was prepared by calcining the mixture of iron phosphate, lithium carbonate and glucose after mixed. The test of charge-discharge indicates that the sample of LiFePO4 holds the discharging voltage platform 3.4 V, the first charge-discharge specific capacity under 0.1C are 164.6 and 163.6 mAh/g respectively.