Helical carbon fibers (HCNFs) were synthesized by one-step chemical vapour deposition using cupric tartrate as a catalyst at temperature below 500 degrees C. The bound rubber of natural rubber (NR)/HCNFs were also prepared in this study. The results of thermogravimetry-differential scanning calorimetry (TG/DSC) for cupric tartrate nanoparticles show that the transformation of C4H4CuO6 -> Cu reaction occurs at similar to 250-310 degrees C. The characterization of scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and Raman spectrum for the synthesized products confirms that the synthesis of HCNFs is highly temperature-dependent. The straight fibers with the fiber diameter of 100-400 nm are obtained at 280 degrees C and HCNFs can be synthesized at higher temperature, with the coil diameter of 0.5-1 mu m and fiber diameter of 100-200 nm at 380 degrees C, and the coil diameter of 100 nm and fiber diameter of similar to 80 nm at 480 degrees C. The maximum of the bound-rubber content (37%) can be obtained with the addition of similar to 100 wt.% HCNFs in NR, which indicates that the coiled configuration of HCNFs makes a noticeable contribution to the reinforcement of NR/CB system. (C) 2014 Elsevier B.V. All rights reserved.