In this study, ZTA powder is modified by SA with different concentrations (0wt%, 1wt%, 2wt%, 3wt%, 4wt%) for the purpose of improving its properties. The effects of SA on microstructure, particle size distribution and flowability of the ZTA powder are investigated by scanning electron microscope(SEM), laser diffraction analyzer and self-made testing device of the angle of repose. After treatment, the average diameter of the powder decreases, the powder shows better dispersibility and flowability especially when the content of SA is 3wt%. FTIR spectroscopy is employed to evaluate the effect of SA coating on ZTA powder. The results indicate that a covalent bond is formed by the reaction between the hydroxyl group of ZTA surface and carboxyl group of stearic acid. Moreover, the changing of the polarity of ZTA powder can result in a stable dispersion in organic solvents.