The Daoist canon claims that Fengyi and an unknown immortal are the Xiyue immortals. Their records can be found in Tao Hongjing's “Zhenling Weiye Tu” and “Lishi Zhenxian Tidao Tongjian”.
Feng Yi, whose style name was Yanshou, was listed as “Xiyue Zhenren” in Tao Hongjing's “Zhenling Weiyeyu” and “Lishi Zhenxiantaidao Tongjian”. “Lishi Zhenxian Taitao Tongjian” says that he was born in the same generation as Li Shan. As a young man, he was already well versed in the ways of yin and yang and was skilled in divination. The King of Xuan heard of his name and made him the Zhuxia Shi. Seeing that the stars were behaving abnormally, he feared that great calamity was imminent, so he feigned illness and resigned from office, devoting himself to cultivation in order to cultivate his character and prolong his life. First, he met the Immortal Deng Zhenren, who taught him the way of the Divine Spirit in the Purple Script. Later, he met the Immortal Peng Zong, who taught him the Supreme Hidden Script. At the age of 80, he finally cultivated himself and became immortal. In the spring of the 20th year of the Tongping King (751 BC), he ascended to heaven and left. The Jade Emperor sent an immortal official to greet him, and he was given the title “Immortal of the Western Mountains”. He went upstream to Shangqing, and entered and left without doing anything.
The biography of the other Xiyue Zhenren is unknown. According to the “Historical Record of True Immortals”, he once retreated to Mount Jiao to learn Taoism. After seven years of cultivation, he met the Taiji Zhenren, who gave him a wooden drill and a stone plate about five feet thick, and warned him that “if the stone plate is worn through, immortality will be attained”. So he used the wooden drill and diamond plate with all his strength day and night for 47 years, and finally drilled through the stone. Taiji Zhenren even taught him how to make a pill of immortality with golden liquid, which, if taken, would enable the person to ascend to heaven. Tao Hongjing's “Zhenling Weiyeh Tu” listed him as “Xiyue Zhenren”, and since then, Taoism has called him Xiyue Zhenren.

道经中指称冯夷和一个不知名的仙人为西岳真人。其记载均见于陶弘景《真灵位业图》和《历世真仙体道通鉴》之中中。
冯夷，字延寿，陶弘景《真灵位业图》列为“西岳真人”。《历世真仙体道通鉴》则称其生于同代，骊山人。少时即通晓阴阳之事，精于占卜之法。同宣王闻其名，以其为柱下史。因见星象失常，恐大祸即至，于是诈病辞官，潜心修炼，以求养性延命。先遇邓真人，授以灵书紫文宝神之道。后遇彭真人(即彭宗)，授以太上隐书。八十岁时，终于修道成仙，于同平王二十年(前751年)春升天而去。玉皇大帝遣仙官下临迎接，封其为“西岳真人”，上游上清，出入无为。
另一位西岳真人其身世不详，《历世真仙体道通鉴》称其曾隐居焦山学道，修炼七年之后，遇见太极真人，得授其木钻和一厚约五尺的石盘，并告诫其“石盘穿，仙可得”。于是全力以木钻钻石盘，昼夜不停，历经四十七载，终于钻尽石穿。太极真人连授其金液还丹，服之即度世升天。陶弘景《真灵位业图》列为“西岳真人”，自此道教即称之为西岳真人。