Abstract: In Tang Dynasty, Daoists undertake the academic tradition of Daoism in the Han Dynasty, used the Yijing to explain elixir thoughts and practice, which influenced by the Zhou Yi Can Tong Qi of Wei Boyang. In Tang Dynasty, there were not only Daoists who explained and elucidated Zhou Yi Can Tong Qi, but also many Daoist scriptures on alchemy referred to the thoughts and concepts of Yijing, which demonstrated a profound understanding of Yi ideology. This paper, by examining Taoist scriptures of elixir in the Tang Dynasty, finds the studies of elixir and Yi are consistent in views of life, trigrams in the Yijing has a close relationship with Taoist elixir, and there exists a correspondence between Guaqi theory and heat control in elixir practice.

Key words: Tang Dynasty, Daoism, Ideology of Yi