The Bizen Kokubunji Temple was constructed in the 8th century, in Maya, Akaiwa City, Okayama. Only foundation stones are preserved. Geological characteristics of the foundation stones suggest that they are collected from mountain area of Maya, about 300 to 800m west from the site. The similarity of the foundation stones and the rocks Maya are identified by the following characteristics. 1) Assemblage of rock types (high grade welded tuff breccia, tuff breccia, tuffaceous sandstone and conglomerate) are the same. 2) Lithology of the 3 rock type of the foundation stones and the rocks from Maya are the same. 3) Rheomorphic flow structures are developed in both high grade welded tuff breccia. 4)Mudstone fragments are contained in both high grade welded tuff breccia tuff breccia.