Ni3Sn2 nanocrystals are encapsulated in carbon nanofibers (CNFs) to form NiSn/CNFs hybrid, using a facile electrospinning method followed by thermal treatment. Compared with pure CNFs and Ni3Sn2 nanoparticles, the resultant NiSn/CNFs hybrid exhibits significantly enhanced microwave absorption performance in terms of high reflection loss and wide bandwidth. The introduction of Ni3Sn2 in CNFs can effectively regulate the microwave absorption performance of CNFs. Interestingly, an optimal content of Ni3Sn2 in the NiSn/CNFs hybrid leads to an unusual dielectric behavior which endows the hybrids with strong reflection loss, especially in high frequency range. When Ni3Sn2 loading was 52.26 wt%, a maximum reflection loss (RL) of 39.81 dB was obtained at 7.36 GHz. Moreover, a wide frequency range with RI, peak value above 10 dB was achieved from 12.76 to 18 GHz. This excellent microwave absorption performance of NiSn/CNFs hybrids can be attributed to their large numbers of electrical pathways which can dissipate microwave energy into heat effectively as well as dielectric relaxation and interface scattering. (C) 2016 Elsevier B.V. All rights reserved.