Alumina is an inorganic material, depending on it’s tructures and purities so that it is widely used in technical ceramics, catalysts, catalyst supports, ion exchange, bioceramics and other fields. The micromorphology of alumina determines its application in high technology and value-added industry and its development prospects. This paper gives the new method to synthesize ultra high-purity alumina α-Al2O3(99.9%) using ultrasonic spray pyrolysis technique from aluminium nitrate solution. The study of microscopic images, mapping analysis, and XRD patterns revealed that the alumina was separated spherical particles with a thin layer ball-shaped structure that metal oxide was uniformly distributed in the wall of hollow sphere particles and average size about 800-900 nm.