Zhang (730 (year) ~ 8 10), born in Wuzhou (now Jinhua, Zhejiang), was born in Guiling, Han nationality, and was nicknamed "heavy smoker" and "Xuanzhenzi". Famous Taoist priest, poet and poet in Tang Dynasty. At the age of sixteen, he took the imperial examination and was awarded the title of "He Zhi" by Tang Suzong. He was demoted to Nanpu Wei for his crime and was pardoned soon. Since then, he has seen through the world of mortals, wandered the rivers and lakes, and lived in seclusion in Chishan Town, Qimen. His brother Zhang Heling was worried that he wouldn't come back from the earth, so he built a small house in the east of Yuezhou (now Shaoxing) for him to live in. He was given a handmaiden in history, and Zhang married them and named them Yuqiaoqing. He knows a lot about literature and art, and is good at poetry, painting and calligraphy, playing drums and flute. During his seclusion, he devoted himself to observing and studying nature, exploring Taoist Hyunri and academic writing. He has many works, the most famous of which is Fifteen Volumes of Taiyi. In addition, there are twelve volumes of Xuanzhenzi with 30,000 words. Most of his books have been lost, and today there are only three volumes of Xuanzhenzi. This is a Taoist book, which reflects the Taoist view of nature. When expounding Taoist thoughts in books, natural science knowledge is often used as an argument.