The Ultimate Way Scripture of Yin Xi 无上妙道文始真经

Originally titled Guanyinzi.

It is traditionally attributed to Guan Yin, the magistrate of Hangu Pass during the pre-Qin period.

The Hanshu·Yiwenzhi (Book of Han·Treatise on Literature and Arts) recorded nine chapters of Guanyinzi; however, the book was not listed in any official history or bibliographic records of the Sui and Tang dynasties and had long been lost. The existing version of Guanyinzi, in one volume, is included in the Benwen (Original Text) category of the Dongshen Section of the Daozang (Daoist Canon). According to textual research in Yu Jiaxi’s Siku Tiyao Bianzheng (Critical Analysis of the Annotated Bibliography of the Complete Library of the Four Treasuries), the book was actually an apocryphal work compiled under a pseudonym by a literatus of the Southern Song Dynasty, dating back to the reign of Emperor Xiaozong of the Song Dynasty. It is divided into nine chapters: Yiyu (Pervading Space), Erzhu (Two Pillars), Sanji (Three Extremes), Sifu (Four Talismans), Wujian (Five Mirrors), Liubi (Six Ladles), Qifu (Seven Cauldrons), Bachou (Eight Counters) and Jiuyao (Nine Elixirs).

The Ultimate Way Scripture of Yin Xi

The book incorporates ideas from Confucianism, Daoism and Immortalism, expounding on the Dao of cultivating the body, spirit, nature and destiny. It contains alchemical terminologies such as "infant and maiden" and "crimson palace and white tiger", and also adopts Buddhist thoughts.

Tan Xian, in Volume Five of his Futang Riji (Diary of the Return Hall), criticized the book for its mediocre phrasing and stated that "many passages overlap with the Yuanjue Jing (Sutra of Perfect Enlightenment) and the Lengyan Jing (Shurangama Sutra)".