Ultrafine aluminum nitride (AlN) powders were obtained by chemical vapor deposition via AlCl3-NH3-N-2 system operated at various temperatures and at a same 200 cm(3)/min flow rate of NH3 and N-2, respectively. It has been shown that when the reaction temperature of AlCl3 and NH3 was above 600 degrees C, then crystalline AIN powder can be formed; whereas, amorphous AIN was obtained with NH4Cl if reacted in a lower-temperature zone of the reaction chamber. The amorphous AIN powder was heat treated at 1400 degrees C under NH, and N-2 atmosphere for 2 h, then the crystalline phases of the obtained powder belong to a single phase of AIN; a mixture of A1N and Al2O3 and only AlON, respectively. On the other hand, if crystalline AIN powder is heat treated at 1400 degrees C under N-2 atmosphere for 2 h, the crystalline phases were composed of the major phase of AIN and a minor phase of Al2O3. The morphology, particle size and agglomerate size of the AIN powder were strongly dependent on the heat-treatment temperature. The particle size of AIN powder increases from 28.1 to 45.0 nm, as the heat treatment temperature increases from 800 to 1400 degrees C.