Atomization of spray and spray characteristics of aero-engine air-blast atomizer affect to improve combustion characteristics, that is, combustion efficiency, emission performance and flame stability. Air-blast atomizer is widely used atomizers for aero-engine due to the benefits such as high-dispersion of spray, generation of smoke is little under high-load condition. However, droplet of spray increases with decreasing in atomizing air flow rate. The purpose of this study is to develop the air-blast atomizer, which excellent spray with uniform and small droplets are obtained under low atomization air flow rate. Hence, the effects of supply methods of atomizing air, existence of swirling flow and atomizer design on atomization of spray were investigated.