For estimation of particle density and mixing ratio, settling experiments were carried out by the buoyancy weighing-bar method. The JIS Test Powders 2, GBL30 and GBM30, which had the same particle size distributions and different densities, were used as sample particles. Glycerol solution was used as dispersion liquid. The density of the glass beads measured by the buoyancy weighing-bar method was similar to that measured with a pycnometer. The density distribution of the glass beads mixtures could be estimated by the buoyancy weighing-bar method.