Ben cao gang mu (Compendium of Materia Medica) is a systematic encyclopedia of traditional Chinese medicine before the 16th century. The work, in 52 juan of text and two juan of illustrations, consists of 1,892 entries, 374 of them added by the author and compiler Li Shizhen (1518−93). Included are about 11,000 prescriptions. It is a priceless legacy of the treasury of Chinese medicine and still applicable. Li Shizhen completed the first draft of the text in 1578, but it was not published until the 21st year (1593) of the Wanli reign of the Ming dynasty, after his death, when it was printed by Hu Chenglong in Jinling. The Jinling copy is the earliest version, drawn and proofread by the Li family and considered the original edition. At present it is kept in the Shanghai Library and in the library of the China Academy of Traditional Chinese Medicine in Beijing. In the 31st year (1603) of the Wanli reign, the work was reprinted in Jiangxi. The later editions were all based on the 1603 edition and spread widely throughout the country. The original 1590 preface by Wang Shizhen (1526–90), the reprint preface by Zhang Dingsi dated 1603, the editorial guide, table of contents, the start of juan one, and illustrations are shown here. Ben cao gang mu was inscribed on the UNESCO Memory of the World Register in 2011.