This book is a calligraphic theory writing written by Xiang Mu of Ming Dynasty. The entire book has a total of 17 articles, including: Shu Tong, Gu Jin, Bian Ti, Xing Zhi, Pin Ge, Zi Xue, Gui Ju, Chang Bian, Zheng Qi, Zhong He, Lao Shao, Shen Hua, Xin Xiang, Qu She, Gong Xu, Qi Yong and Knowledge.