Nanocrystalline titanium carbonitride (TiCN) was successfully synthesized at low temperature (450 degrees C) via a chemical metathesis route using the readily attainable TiCl4, CaC2 and NaN3 as source materials. X-ray powder diffraction indicated that the product was cubic TiCN with a lattice constant a = 4.252 angstrom. Transmission electron microscopy revealed that the crystals were composed of spherical particles with the diameter of 66 nm. X-ray photoemission spectra analysed that the atomic ratio was good agreement with the TiC0.4N0.6 stoichiometry. The possible formation mechanism was investigated.