Iron oxide/carbon nanofibers (FeOx/CNFs) were prepared by electrospinning FeCl3.6H(2)O-polyacrylonitrile (PAN) precursors and heat treating at 400, 600, 800, 1000 degrees C. As carbonization temperature increased, granular FeOx gradually migrated from nanofiber interior with effectual contacts between electrolyte and active materials rising at first and then falling; Oxidation states of iron in FeOx/CNFs changed from Fe2O3 to FeO and Fe with an improvement of capacity retention and an extra reversible capacity catalyzed by Fe; Graphitization process of carbon matrices proceed with less defective structures and heteroatom contents, leading to an increase of conductivity and a diminution of irreversible reactions during cycling. As systematically studied and compared in electrochemical performance, FeOx/CNFs with FeO, Fe state, highly graphitized carbon matrices and migration structure with FeO and Fe both embedded in and dispersed on carbon matrices presented stable cycling performance with a reversible capacity of similar to 674 mAhg(-1) after 60 cycles and outstanding rate capability. The above trade-off study of all the cooperative factors that affected the electrochemical property might make an effective guidance for preparation of promising FeOx/CNF anodes. (C) 2016 Elsevier Ltd. All rights reserved.