An aerosol process for making aluminum nitride nano-powder by decomposition of single compound diethylaluminun az-ide was described. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to study characters of the A1N powder. It is shown that the process can produce spherical A1N powder with mean particle diameters ranging from 10 to 50 nm at 500-800℃. The generated amorphous A1N powder is characterized by a BET (Brunauer-Emmett-Teller) surface area of 103 m2/g and is very reactive to moisture.