There are several kinds of earthenware in ancient Japan, for example, Jomon pottery, Yajoi pottery, Haji ware and Sue ware. In order to trace their transportation, it is necessary to find out the site where they were produced and characteristics of the site. However, it is only of Sue ware that kiln sites remain. This is the reason Sue ware was selected. The purpose of this study was to find the indicators characteristic of producing districts. X-ray fluorescence analysis was applied to 676 pieces of Sueware shards excavated from 65 kiln sites in the Kyushu Island and the Chugoku district. The Rb, Sr, Fe, K and Ca contents were found to be indicators of the producing districts. Of them, it was shown that Rb was correlated with K, and also Sr with Ca. Therefore, Rb and Sr were found to be the best indicators of the producing districts. The Sueware shards of the Sanyo group were discriminated from that of the Sanin group on the (Rb-Sr) map. The Nobeoka, Miyazaki and Nakatsu groups in the Kyushu Island were mutually discriminated, and also the Ushikubi group from the Tenganji group.