Fe3O4 nanocrystals (NCs) composed of different proportion of {100} and {111} facets were prepared using oleic acid and decanoic acid as surfactant to mediate their growth process. It has been found that the morphology of Fe3O4 NCs can be tuned by changing the ratio of oleic acid and decanoic acid. When tested as the anode materials in LIBs, the Fe3O4 octahedrons obtained after annealing at 450 degrees C was found to exhibit superior electrochemical performances with a high reversible capacity of 882.6 mAh g(-1) at 1 A g-1 over 200 cycles, whereas the Fe3O4 cubooctahedron and cubes bearing poor electrochemical performances. The present results prove that the surface structure of Fe3O4 polyhedrons significantly influence the utilization of Fe3O4 active materials and hence their electrochemical performance although the morphology will be destroyed during cycling.