The Fodingxin Guanyin Sutra is an apocryphal Chinese Buddhist sutra that appeared after the middle of the Tang dynasty. The manuscript consists of three volumes each with separate titles and varying content, though the primary intention of the text is to propagate Avalokitesvara Bodhisattva’s merits through the doctrine of salvation and moral stories. Different versions of this sutra have been found in Dunhuang, in Khara-Khoto, in the cellar of a wooden pagoda in Ying County and among the stones engraved with the Tripitaka at Fangshan. With the publication of the Collection of Khara-Khoto Documents in Britain,more than 20 fragmental documents in Tangut script have been found to be part of the Fodingxin Guanyin Sutra. This paper corrects the titles of some of the fragments and re-collates the pages of the text. The model of textual organization that was used to organize the content of the sutra can be identified as having been borrowed from the sutras on Avalokitesvara written by Zhi Tong, Ghavan Dharma and Bodhiruci in the Tang dynasty. This sutra spread widely throughout north China during the Later Tang and Five Dynasties periods. After having been introduced into the Tangut Empire(or Western Xia), it was translated into Tangut script by the monk Fa Lü sometime prior to the 17 th year of the Tiansheng era(1165 CE). Both Tangut and Chinese versions were popular in the Tangut Empire.