東大寺大仏を建立したことで有名な聖武天皇は，また都を

This study examines the ideas of ancient people about places for placenta rituals in Heijo-kyo, the 8th-century capital of Japan. The placenta is the material that comes out of a woman’s body after she gives birth to a baby, which is necessary to nourish and protect the baby in utero. Traditionally, the treatment of the placenta has been associated with the health and future of the baby, so there are many forms of related ceremonies around the world.

In Japan, placenta rituals took different forms in different periods. In many modern instances, the placenta was wrapped with paper or cloth and put in a pot, then buried underground in an auspicious direction. The pot contained, if the baby was a boy, a brush or an ink stick with his placenta. If the baby was a girl, there was a thread or a needle with her placenta.

Archaeologists have cited placenta rituals in folklore for their interpretations of pottery-buried remains. Many archaeologists have believed pottery was ritually buried around the front door of houses since in folklore, the placenta was frequently put in a pot and buried under the entrance of a house. But placentas were actually buried in various places apart from the front door; for example, in the shade, on mountains, by the roadside, in estates, under the floor, and in lavatories.

The oldest attested pottery-buried remains are found at the capital, Heijo-kyo. It is difficult to determine the purposes of burying earthenware during the Nara period. Yet two major purposes are for ground-purification ceremonies and for placenta rituals. So this paper first attempted to classify them by the kinds and the contents of the ritually buried pottery. The typical pottery used for placenta rituals is Sue ware jars called “Sueki tsubo A”, resembling a medicine pot that was associated with Yakushi or the Buddha of healing. The typical contents of the pottery are ink sticks, brushes and pieces of cloth.

The sites where pottery-buried remains were unearthed are large in size and near the Heijo Palace. This fact suggests that placenta ceremonies were carried out by government officials of the Heijo-kyo capital. And the sites of rituals were not always at entrances, but in many cases around the houses. According to ancient Chinese medical books, burying the placenta in the shade was taboo. But in modern folklore of Japan, the shade was often chosen as the place for burying the placenta, and many placentas were buried under the floors of houses.

In this respect, the sites where pottery-buried remains were unearthed in Heijo-kyo differ from those of placenta rituals as described in modern folklore. We came to the conclusion that though in Heijo-kyo they had their own idea about the placenta burial site, the rituals were typically performed by government officials on the basis of ancient Chinese medical books.