It is a well-known fact that a pioneering mission sent out eastwards by Nestorian Christianity reached to Tang China in 635. This memorable exploit has a particular significance not only for medieval religious history, but also for the study of the cultural exchanges unfolded between China and her neighboring foreign countries. Since then, Nestorian manuscripts from the Dunhuang cave and the text of the Stele Commemorating the Propagation in the Middle Kingdom of the Luminous Religion from Daqin (大秦景教流行中國碑) remain to be the essential documents solely relied upon as the basics of all Nestorian researches. And now, two events, the discovery in Luoyang (2006) of a stone pillar inscribed with Nestorian scripture during the Tang dynasty and the formal publication of 『敦煌秘笈』(『Tonkō Hikyū』, in which a number of cirtainly authentic Dunhuang Nestorian manuscripts kept in the 杏雨書屋/ Kyōu Shooku Library were published) in Japan (2011) would provide a fresh impetus to the Nestorian study of Tang China. Furthermore, when the Tang Nestorian priests elaborated upon their own ideas and beliefs in their translating and propagating procedure, they must have found that borrowing and paraphrasing some similar terms from the Confucian and Taoist doctrines, and especially quoting Buddhist synonym terms in a large amount, are remarkably useful and practically helpful. They had done this to make the Nestorian ideas in their original text fit into the Chinese translation. As to how the Tang Nestorian doctrine had made reference to the Buddhist rituals, it seems there is no such a study for the present. The present paper, mainly based on 『三威蒙度贊』 (Sanwei Mengdu Zan),『尊經』(Zun Jing), and『宣元至本經』(Xuanyuan Zhiben Jing), is aimed to show the aspect of the transformation of the Nestorian doctrine under the impact of the Buddhist ritual texts.
