Carbon-doped LiFePO4/C cathode materials for lithium power batteries were prepared by liquid-state precipitation reaction. Their properties were studied by using XRD, SEM, elemental analysis, FTIR and A.C. impedance tests. The results showed that the samples with olivine structure and 3.4V discharge platform. The tapped density of LiFePO4/C sample could reach 1.42g/cm3, and it had an initiate capacity of 144.6mAh/g at 0.2C, and 93.2% of which remained after 20 cycles. The first discharge specific capacity is 133.5mAh/g at 10C and the capacity decreased 8.76% after 20 cycles.