A laboratory method of producing amorphous powder by fine gas jet impingement of molten Al-Mg-Zn alloy is described. The powder has been characterized by X-ray diffraction and differential thermal analysis (DTA) techniques. The grain size of the powder varied from 5 to 80 mum. The fine grains (size upto similar to 20 mum) are completely amorphous. However, large grains are partly amorphous. Using the DTA technique, glassy-crystalline phase transition temperature T-g is found to be 473.6 degreesC. Vickers hardness of the grains is in the range 215 to 255 kg/mm(2).