Ichiji Kinrin (Ekākṣara-uṣṇiṣacakra, “one-syllable golden-wheel”) is a term referring to the supreme state of the Buddha by which the Lord Buddha is likened to Tenrin-ō (Cakravarti-rājā, sovereign ruler whose chariot wheels roll everywhere without hindrance), the ruler of the secular world, so termed because the virtue of this Buddha is represented by the “ esoteric syllable” bhrūṃ. The Ichiji Kinrin Mandara is a mandala of deities centering around the Ichiji Kinrin Buddha, and is usually shown with the Buddha surrounded by the Seven Treasures proper to Tenrin-ō. There are two kinds of the Ichiji Kinrin Buddha, namely Shaka (Śākyamuni) Kinrin and Dainichi (Vairocana) Kinrin. Historically Shaka Kinrin was first to appear in the Hybrid Esoterism, and Dainichi Kinrin developed from it after the Pure Esoterism was established. Sūtras concerning Ichiji Kinrin were translated in China during a short period from the Middle to Late T'ang, and the translated sūtras, together with Ichiji Kinrin Mandaras, were brought back to Japan by priests who were sent to China for Buddhist studies. The Ichiji Kinrin Service, in which the object of worship was an image or mandara of Ichiji Kinrin, was a very important ritual in the Esoteric Buddhism : it was said that during this ritual all other rituals held within the distance of 500 yojanas from it were useless. The sūtras regulate that an Ichiji Kinrin Mandara should be composed with either Shaka Kinrin or Dainichi Kinrin as its center, but in Japan there exists no example of Shaka Kinrin either in mandala form or as an independent image. Of mandalas centering around Dainichi Kinrin, there are roughly six types each with slight variations (cf. Table 1). Existing specimens belong to three of these six, namely: (1) mandala with the Seven Treasures and the Butsugen (“Eye of the Buddha”), (2) with these eight deities on an eight-petalled lotus flower, and (3) with the Seven Treasures alone. As far as the present writer knows, there exist ten examples of Ichiji Kinrin Mandara in Japan. Five of them belong to the group (1), two to (2) and three to (3). Of the two mandalas formerly in the Masuda Collection, A (Pl. III) is typical of the group (1). Dating from the second half of the twelfth century, it is the oldest of the kind and representative of the Late Heian Period notable for its beautiful colouring and delicate, gentle portrayal. Falling under the same classification but somewhat different in composition is the one in the Henjōkō-in (Pl. IV), in which blue is the keynote of colouring. Its style of brushwork as well as colours evidently show characteristics of the Kamakura Period. This painting has an inscription on its back dated equivalent to A. D. 1220, proving that it dates back to that year if not earlier. It is noteworthy that this piece has much in common with contemporary paintings existing in the Daigo-ji. The mandala B of the former Masuda Collection (Pls. I & II), belonging to the group (3), is very unique. In the portrayal of the central deity, the Seven Treasures and the sacred clouds, and the manner of colouring in which gradated washes of “shading” are employed frequently, it shows a style closely resembling that of Tun-huang paintings of the T'ang to Five Dynasties. Obviously it is a faithful copy of a Chinese prototype. Its colour and drawing suggests a date somewhere near the end of the twelfth century. The writer describes in details the results of her study on the above-mentioned three paintings which have heretofore been left relatively ignored (the one illustrated in Pl. IV having never been published), and emphasizes the significant positions which they hold in the history of Japanese Buddhist art. In comparison with these three, the other specimens, all from the Kamakura Period or still later, are not too important, but brief iconographic and stylistic discussions are given also on them.