Chen Tuan (87 1-989), whose name was Tu Nan, was Fu Yaozi, and his nicknames were Mr. Baiyun and Mr. Yi Xi. He was a well-known Taoist scholar and health care practitioner in the Northern Song Dynasty, and highly praised the study of Huang Lao.

In the 12th year of Tang Xiantong (87 1), Chen Tuan was born in zhenyuan county, Bozhou (now Luyi County, Henan Province) (or Chongkan County, Yunpu Prefecture, now Chongkan Town, Tongnan District, Chongqing) [1]. In the first year of Tang Wende (888), Chen Tuan was summoned by the emperor and was named "Qing Xu Chu Shi". In the seventh year of the Five Dynasties and the third year of Changxing at the end of the Tang Dynasty (932), Chen Tuan went to Luoyang to take the exam, and was named. In the second year of Qing Tai in the late Tang Dynasty (935), he lived in seclusion in Jiushiyan, Wudang Mountain, determined to follow the Tao. He is the author of books on physiognomy such as Guijian and Psychology. In the second year of Tianfu at the end of Jin Dynasty and the first year of Shengyuan in Southern Tang Dynasty (937), he returned to ancient Shu and studied nose lock with He Changyi, the power of Guandu in Tianqing, Qiongzhou. He has written monographs such as "Fetal Breathing Tactics" and "Zhi Xuan Pian". At the end of Jin Dynasty, in the fourth year of Tianfu (939), he went to Emei Mountain to give lectures and was named "Emei Real Person". He is the author of "Watching the Sky" and so on. He is a teacher from Ma Xiu, engaged in the study of Yi-ology, and has written Notes on Yi Yi Dao's Righteousness, Yi Long Tu Xu, Tai Chi Yin Yang Shuo, Tai Chi Tu and Congenital Fiona Fang Tu, etc. And most of the works circulating now are under the guise of names. In the 12th year of Tianfu at the end of Jin Dynasty (947), Chen Tuan lived in seclusion with Taoist Ma Yi in yuntaiguan, Huashan. I often go back and forth between Huashan and Wudang Mountain. In the third year of Xiande in the later Zhou Dynasty (956), he was summoned by Chai Rong, Zhou Shizong, and was appointed as an "admonition officer". He refused to be an official and was given "Mr. Baiyun". In the second year of the Northern Song Dynasty (977), Song Taizong Zhao Guangyi summoned Chen Tuan. In the first year of Yongxi in the Northern Song Dynasty (984), Emperor Taizong summoned Chen Tuan again and named him "Mr. Yi Xi". In the early years of the Northern Song Dynasty (988), he died in the Zhangchao Valley of Huashan at the age of 1 18.