FeCo/C hybrid nanofibers (FeCo/C HNFs) with short multi-walled carbon nanotubes grown on the nanofiber surfaces have been prepared by electrospinning combined with stabilization and carbonization. The in-situ formed FeCo nanoparticles uniformly disperse along nanofibers and are encapsulated with ordered graphite layers. It is found that the as-prepared FeCo/C HNFs exhibit excellent microwave absorption performance with low density and small absorber thickness. Reflection loss exceeding -20 dB can be obtained in a wide frequency range of 7.2-18 GHz for the silicone composites containing only 5 wt. % FeCo/C HNFs as filler by choosing an appropriate absorber thickness between 1.4 and 3.0 mm, and the minimum reflection loss reaches -47.5 dB at 16.6 GHz for a 1.6 mm absorber layer, indicating that the FeCo/C FINFs can be a promising candidate for lightweight, highly-efficient and stable microwave absorbing materials in X- and Ku-bands. (C) 2014 Elsevier Ltd. All rights reserved.