The angle of repose (AOR), aerated bulk densities (rho(A)), and tapped bulk densities (PT) Of 18 fractions of spherical glass beads of mean particle size of 12-190 mum were studied. The ratio of AOR to rho(A) ("weighted" AOR) was found not only to be correlated well with the ratio Of rho(T) to rho(A), (which is referred to as the Hausner Ratio, HR) for the free-flowing powders, as suggested by Wouters and Geldart (Part. Part. Syst. Characterisation 13 (1996) 254), but also to be able to extend to cover powders showing degrees of cohesiveness. Results of this study suggest that rho(A) in the "weighted" AOR could be replaced by PT in order to reduce errors caused by the sensitivity Of rho(A) measurements. The minimum fluidization velocity (U-mf) and the minimum bubbling velocity (U-mb) of the powders studied were determined in a cylindrical fluidized bed. The results demonstrated that the ratio of AOR to bulk densities or to HR exhibited a strong exponential decaying characteristics with U-mf and U-mb with good correlation coefficients. It is believed that U-mf and U-mb predicted based on the angle of repose and bulk densities are more realistic since the methods for the measurements of AOR and bulk density bear some degrees of "dynamic" aspects of the powders which are responsible for their fluidization behaviour.