Abstract
Intertextuality (mutual illustration) is a common rhetorical device in ancient Chinese and has been used many times in Laozi (Dao Dejing). Intertextuality (mutual illustration) is of unique significance for understanding the linguistic structure and philosophical thoughts of Lao-zi. According to the current research on mutual illustration rhetoric on ancient Chinese, the forms of this rhetoric in Laozi can be divided into mutual illustration of single sentence, of multiple sentences and of ellipsis and antisense. There are only two references to mutual illustration in the annotations of Laozi in the past dynasties, and most of the commentators ignore the importance of mutual illustration in understanding Laozi. By interpreting Laozi through mutual illustration rhetoric, we can make innovations in understanding methods, understanding contents and philosophical thoughts.