Ceramic samples from eight kiln sites situated in the western part of Japan (sites of Bizen and Katsumata in Okayama prefecture; Tamba in Hyogo prefecture; Mino in Gifu prefecture; Sanage, Atsumi, Toyohashi and Tokoname in Aichi prefecture) were examined by x-ray fluorescence analysis. Significant differences of the patterns of element distribution were found among the kilns studied, and particularly the ratios of calcium to potassium and rubidium to zirconium were significantly different.