Pure trigonal-shaped TiN nanocrystals with the size of 30-50 nm were synthesized from a metal-catalyzed reduction-nitridation (MCRN) route at 350degreesC for 6 h, which used TiCl4 and NaNH2 as the starting materials and Mg metal as the catalyst. The obtained sample was characterized by XRD, TEM, and XPS. The effect of the metallic catalyst on the formation of the trigonal-shaped TiN nanocrystalline was discussed.