Flowability of spherical glass beads having mean particle size (dp) ranging 20-170 mu m were studied. Their aerated ip,) and tapped bulk (rho(tau)) densities, angle of slide (sigma(s)), and angle of repose (beta) were measured. While a linear relationship was found to exist between sigma(s) and dp, it was, on the other hand, shown that beta and dp exhibited an exponential decaying characteristic. It was also demonstrated that the angle of slide and the angle of repose of a given powder were conveniently correlated with its Hausner ratio, which is usually defined as the ratio of the tapped bulk density to the aerated bulk density. Explanations in terms of powder matrix and interparticle forces were attempted for the behaviour of the powders found in the investigation.