Helical carbon nanofibers/silica (HCNFs/SiO2) was successfully synthesized using a novel two-step method, namely by low-temperature graphitization of HCNFs and subsequent in-situ grafting of silica nanoparticles (about 36 nm) on incompletely-graphitized HCNFs. The results confirm that the orderly array of graphite layers in local region was obtained after low-temperature graphitization at 1000 degrees C, which provides active growth sites for grafting silica nanoparticle via O-H center dot center dot center dot pi interactions. Compared with common carbon black (CB) N330 and single-phase HCNFs filler, HCNFs/SiO2 has the maximum of the bound-rubber content (43.3%) in NR system, due to its dual-phase combination of carbon/silica and the sophisticated carbon coil structure.