Ben cao pin hui jing yao (Collection of the essential medical herbs of materia medica) was compiled and illustrated by imperial order of Emperor Xiaozong (ruled 1487−1505) of the Ming dynasty. The manuscript was completed in the 18th and last year of his reign, called Hongzhi (1505). It was the only officially published work on materia medica. After Emperor Xiaozong died, the manuscript was kept in the imperial court and not printed for more than four centuries. However, a number of expertly copied manuscripts with color illustrations did appear. Stories about the compiler, the physician Liu Wentai, also circulated. It was said that Liu was an executive medical official at the Imperial Academy of Medicine during the time of Xianzong (1465−87) but was demoted to the rank of administrative medical assistant for “providing inappropriate dosage, causing damage to the emperor” and was further demoted to court physician. It was Liu who led the compilation efforts and the work was presented to the court with his signature. Many other compilers contributed, most of whom were physicians at the academy and a few scholars from the Secretariat. Eight renowned artists, including Wang Shichang, undertook the illustrations. The contents are drawn from Zheng lei ben cao (Classified materia medica from historical classics for emergency), Qin shan zheng yao (Principles of correct diet), Shao xing ben cao (Shao xing materia medica), and other works, thus the word “essentials” in the title. The work, in 42 juan, lists 1,815 herbal medicines, grouped in 10 categories (jade, grass, trees, humans, animals, birds, insects and fishes, fruits, grains, and vegetables). There are 1,367 color illustrations of medicines. The compilation follows that of Zheng lei ben cao but also uses the stylistic rules of Huang ji jing shi (Book of the supreme principles governing the world) written by Neo-Confucian philosopher Shao Yong (1011−77) of the Northern Song. The drugs are divided into two grades, using the conventional 24 rules for descriptions and discarding the traditional way of inserting layers of annotations. The contents cover the authentication, production, composition, and pharmacodynamics of medical ingredients, and related topics, such as folk culture, ideas of health, and geographic environments. The medical knowledge of the compilers and engravers was limited and the work was compiled and illustrated quickly, over a period of one and a half years. Thus the clarity of textual research and information on additional medical drugs is less than praiseworthy. In some cases illustrations and texts do not match. For example, the image of a kiwi is labeled as a peach. These defects affected the book’s scholarly value, even though it was the largest encyclopedia with color illustrations and used images from Zheng lei ben cao. Its highest achievement is the 668 new illustrations. In addition, 144 revised illustrations provide further details of everyday objects familiar to the painters, such as vegetables, fish, shellfish, birds, animals, insects, and popular medicines. The painters at the academy also could paint from life, especially exotic animals, such as lions, elks, and peacocks. These splendidly realistic images with colorful brushstrokes are the essence of this work.