Li3V2(PO4)3/C has been synthesized by a simple one-step carbothermal reduction technology using LiH2PO4, V2O5 as the raw materials and sucrose as carbon source. X-ray diffraction (XRD) and scanning electron microscope (SEM) measurements showed that Li3V2(PO4)3/C synthesized by one-step carbothermal reduction had monoclinic structure. The structure and particle-size of the as-prepared Li3V2(PO4)3/C can be adjusted by the amount of carbon content, sintering temperature and sintering time in the synthesis processes. Li3V2(PO4)3/C prepared with a carbon content 0.4, sintering temperature 800°C and sintering time 20 h showed the largest discharge capacity 121.4mAh.g−1 and an capacity retention rate of 98.3% after 50 cycles at 0.5C. The Li3V2(PO4)3/C obtained also exhibits an excellent rate capability with high discharge capacities of 111.0 mAh.g−1 at 2.0C and 102.1 mAh.g−1 at 5.0C.