In this study, experimental study on the atomization process is taken. Variations of melt flow rate and partice size distribution with operating conditions such as aspiration pressure, gas and melt flow rate, outer diameter and protrusion length of orifice and gas pressure have been studied. The melt flow rate is determined mainly with aspiration pressure P_a and expressed as following : mfr=K√2πD²_i/4·[gh+·P_a/p]^½, where K is constant, D_i, g, h, and p is orifice inner diameter, gravitational acceleration, height of melt head and density of the melt respectively. With increasing protrusion length, the shape of free film has changed from conical to cylindrical form, and the spray cone become more stable. The thinner the free film, the finer powder is obtained. Powder size decreases with increasing the ratio of gas folw rate to melt flow rate and the outer diameter of orifice, and with decreasing the protrusion length of orifice.