Amakusa pottery-stone was ground by a dry ball-mill process, and some properties of the ground powder, plastic body, and sintered body obtained by this process were investigated and compared with those of products by conventional stamp- and wet ball-mill process. Dry ball-mill powder produced relatively large amounts of particles 30μm in size, with a particle size distribution similar to that found in the stamp-mill process. In the dry ball-mill powder, very fine particles ( 30μm) containing quartz for about 92-95mass%. These components were similar to those found in the stamp-mill process. The plastic body of dry ball-mill had a high fluidity, similar to the stamp-mill body. Fluidity decreased in the dry ball-mill body as the water content decreased; however, the fluidity increased with increasing grinding time. Better properties were obtained in the sintered body by dry ball-mill as compared with that of a stamp-mill sintered body; however, these properties were less improved than in a wet ball-mill body. The relation between the value of sintered body properties and the amount of particles >30μm in each grinding powder obeyed a simple linear relation.