alpha -Si3N4 whiskers with diameters of about 0.1 mum and length of 3-5 mum were fabricated through combustion synthesis route under very low nitrogen pressure of 0.5-1 MPa. The measured maximum combustion temperature is about 1863 K which is rather lower than the adiabatic temperature (about 4400 K) and the decomposition temperature (about 2170 K) of Si3N4 under atmospheric pressure. The addition of NaN3 catalyst plays a key role in the formation of alpha -Si3N4 whiskers under such low nitrogen pressure. (C) 2002 Published by Elsevier Science B.V.