The relation between the use of porcelain stone and the invention of Chinese porcelain is described. The characteristics of porcelain stone and kaolin and their important role in the development of southern porcelains are discussed. As porcelain stone, which mainly consists of quartz and sericite, occurs widely in south China, the ancient southern porcelains were of a highly siliceous nature. From the beginning of the Yuan through to the Qing Dynasty more and more kaolin was added to the bodies to improve the quality of Jingdezhen porcelain. The glazes in south China were prepared from a mixture of porcelain stone and grass-plus-wood ash or glaze ash. The raw materials used in the north for making bodies were mainly various kinds of clay minerals. Feldspar, quartz and dolomite or calcite were used for northern glazes. -- AATA