On a dry river-beach of the upper stream of the Narawa river (成羽川) in Bicchucho (備中町), Okayama prefecture, there is a monument called "Kasagami no Mojiiwa" (笠神の文字岩). It was set up in memory of the opening of the water way which had been completed in 1307. The details of its construction are engraved on that monument. According to it, I would like to call attention to a stone mason, named Ingyokei (伊行径) who took part in the construction of the water way. He was a descendant of Ingyomatsu (伊行末), a famous mason of the Sung dynasty who had come to Japan and made a contribution to the reconstruction of Todaiji (東大寺). We can find nine stone monuments which are regarded as Ingyokei's works. He started his work in Bicchu and afterward went to Kinki where he left some of his works. In order to study Ingyokei's works, it would be well to classify them into two groups, namely the works produced in Bicchu and the works produced when he left Bicchu. In the same period when Ingyokei was working actively in Bicchu, an anonymous mason who had some relation with Ninsho (忍性), the priest of Saidaiji (西大寺) in Nara, was producing some excellent stone objects in the districts of Hakone and Kamakura. In this article I wish to find out the currents of cultural influence between the western and the eastern parts of Japan during the Kamakura period with special reference to the aforesaid stone objects.