With Al2O3 and graphite as raw materials, CaF2 and B2O3 as additives, AIN whiskers were fabricated by a carbo-thermal reduction method. The fabrication mechanism and growth characteristics of AIN whiskers were investigated. At the beginning of the high-temperatu re fabrication, AIN whiskers grew by the vapour/liquid/solid (VLS) mechanism, and defects existed on the surfaces of the whiskers. In later stages, the VLS mechanism possibly changed to a vapour/solid (VS) mechanism, and the defects disappeared. The orientation of most AlN whiskers was normal to {10 (1) over bar n} (n = 0, 1, 2, 3), and normal to {(1) over bar 2 (1) over bar n} (n = 0, 1, 2). The growth processes of both two-dimensional nucleation and screw dislocations existed at the same time.