Nanocrystalline boron nitride (BN) was prepared by the reaction of BBr3 and NaN3 at 350 degreesC. The morphologies of particles, needles, flakes and solid balls were controlled by solvothermal growth using benzene as solvent. X-ray powder diffraction patterns can be indexed as hexagonal BN with the lattice constants of a=2.502 and c=6.734Angstrom. The products were also characterized by X-ray photoelectron spectrum, fourier transformation infrared spectroscopy, transmission electron microscopy and electron diffraction. (C) 2004 Elsevier B.V. All rights reserved.