Granules were prepared from a dispersed slurry containing binder by means of a rotational disk type of spray dryer, and the size distribution was investigated on the basis of a Balloon Model proposed in the authors' previous papers. It was experimentally confirmed that the granules exhibited broader size distribution than the initial droplets, and that this tendency was enhanced with increasing binder content. This indicated that the shrinkage ratio of the droplet size to the granule size increased with smaller initial droplet size and lower binder content. Analysis by the Balloon Model indicated that the shrinkage ratio of smaller droplets increases without being greatly affected by binder content due to the spray drying characteristics of the equipment, but the shrinkage ratio of larger droplets decreases with increasing binder content due to stronger interparticle cohesiveness.