AIN nanocrystals have been prepared in organic solvent at atmospheric pressure. The results of measurement on the samples indicated that the sample is a mixture of hexagonal and cubic aluminum nitride (AIN) nanocrystals. All of X-ray diffraction, Fourier transformation infrared spectroscopy and selective area electron diffraction measurement results have proved the existence of cubic AIN. The photoluminescence spectrum of AIN nanocrystals is composed of a rather intense peak at 475 nm and a broad weak peak at 550 nm. (C) 2002 Elsevier Science B.V. All rights reserved.