LiFePO4/C cathode materials were synthesized by Sol-gel method under the same process conditions using different water-soluble lithium source (LiOH, Li2CO3, LiNO3). The phase of synthesized powders were characterized by XRD; and the electrochemical performance of the material was investigated by measurements of cyclic voltammetry, AC impedance measurements, charge and discharge. The results show that the synthesized LiFePO4/C using LiOH as the lithium source has high electrochemical reversibility and low internal impedance. The specific discharge capacity is 147.5mAh/g under the discharge at 0.2C rate. It also has high stability of cycle capacity, and almost no attenuation after 30 cycles. So it has the excellent electrochemical performance.