Olivine type LiFePO4 cathode material was synthesized by solid-state reaction method including one-step heat treatment. To improve the electrochemical characteristics, graphite nanofiber (GNF) was added into LiFePO4 cathode material. The structure and morphological performance of LiFePO4 were investigated by X-ray diffraction (XRD) and a field emission-scanning electron microscope (FE-SEM). The synthesized LiFePO4 has an olivine structure with no impurity, and the average particle size of LiFePO4 is about 200~300 nm. With graphite nanofiber added, the discharge capacity increased from 113.43 mAh/g to 155.63 mAh/g at a current density of 0.1 mA/cm2. The resistance was also significantly decreased by the added graphite nanofiber.