LiFePO4-C nanoparticles were synthesized by a hydrothermal method and subsequent high-energy ball-milling. Different carbon conductive additives including nanosized acetylene black (AB) and multi-walled carbon nanotube (MWCNT) were used to enhance the electronic conductivity of LiFePO4. The structural and morphological performance of LiFePO4-C nanoparticles was investigated by X-ray diffraction (XRD) and scanning electron microscopy. The electrochemical properties of LiFePO4-C/Li batteries were analyzed by cyclic voltammetry and charge/discharge tests. XRD results demonstrate that LiFePO4-C nanoparticles have an orthorhombic olivine-type structure with a space group of Pnma. LiFePO4-C/Li battery with 5 wt% MWCNT displays the best electrochemical properties with a discharge capacity of 142 mAh g−1 at 0.25 C at room temperature.