This article studies the preparation of spherical alumina with irregular shape powder by radio frequency (RF) induction plasma. The single factor method is adopted to discuss parameters of spherical alumina prepared by RF plasma process. Studies on the impact on spherical alumina powder of gas flow, negative pressure ventilation, powder feed rate and dispersion methods and other major preparation process parameters are made. Scanning electron microscope (SEM) is used to observe and assess the effect of spheroidization on the bulk density and tapped density. When the alumina is getting through the RF plasma torch in very short time, the particles are heated and melt into droplets. After rapid cooling, spherical solid particles form.