Compendium of Materia Medica was a massive literary undertaking. Li's bibliography included nearly 900 books. Because of its size, it was not easy to use, though it was organized much more clearly than others that had come before, which had classified herbs only according to strength. He broke them down to animal, mineral, and plant and divided those categories by their source. Dr. S. Y. Tan says: “his plants were classified according to the habitat, such as aquatic or rock origins, or by special characteristics, e.g. all sweet-smelling plants were grouped together.”
Li had exemplary recording techniques. The medicinal plants and substances in the Compendium of Materia Medica were clearly organized and categorized. With every entry, he included:
● “Information concerning a previously false classification;
●Information on secondary names, including the sources of the names;
●Collected explanations, commentaries and quotes in chronological order, including origin of the material, appearance, time of collection, medicinally useful parts, similarities with other medicinal materials;
●Information concerning the preparation of the material;
●Explanation of doubtful points;
●Correction of mistakes;
●Taste and nature;
●Enumeration of main indications;
●Explanation of the effects; and
●Enumeration of prescriptions in which the material is used, including form and dosage of the prescriptions.”
In addition to writing Compendium of Materia Medica, Li was one of the first to recognize gallstones, use ice to bring down a fever, and to use steam and fumigants to prevent the spread of infection.
