SiCN nanowires are synthesized by pyrolysis of hexamethyldisilazane (HMDSN) using ferrocene as a catalyst precursor at 1200 degrees C in a flowing argon atmosphere on the surface of mullite substrate, polycrystalline alumina wafer and quartz tube. In oxygen-contained argon atmosphere, SiCN/SiO2 nanocables are synthesized. The as-synthesized products are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and high-resolution electron microscopy equipped with energy dispersive X-ray spectroscopy. The lengths of the nanowires and nanocables are in the millimeter range. The diameter of the SiCN nanowires grown on mullite substrate and alumina wafer ranges from about 10-70 nm, while that of the nanowires grown on quartz tube surface is in the range of around 7-10 nm. The diameters of the SiCN/SiO2 nanocables are relatively large. A vapor-liquid-solid growth mechanism of the nanostructures is proposed. The electrical resistivity of a single SiCN/SiO2 nanocable is reported for the first time.