According to legend, The Map of Xuan Ji is a palindrome poem written by the wife of the secretariat in the pre-Qin period (now Tianshui, Gansu), and is often called palindrome poem.
Su Hui's Map of Xuan Ji is 84 1 word, with 29 words in vertical and horizontal directions. When reading vertically, horizontally, obliquely, interactively, forward, backward or backward, they can all be poems. Poems range from three words, four words, five words, six words and seven words, which are very wonderful and widely spread. Her stories about finding true love have also been passed down to this day.