In the process of studying medicine, Li Shizhen carefully read many medical books and herbal works. He tried to absorb and inherit the achievements of his predecessors. There is a Confucian scholar family named Hao, and there are many precious medical books in the family. Li Shizhen borrowed these precious medical ancient books by virtue of his father's friendship with the Hao family. At the same time, in the practice of practicing medicine with his father, Li Shizhen gradually accumulated rich clinical experience. By comparing ancient and modern times and studying hard, he found some doubts, shortcomings and obvious mistakes in many ancient medical books and pharmacopoeias, which made him have the ambition to rebuild materia medica. After repeated thinking, 1552, he finally decided to rebuild materia medica as the goal.
In order to study materia medica and minimize mistakes, he paid special attention to in-depth practical investigation. He spent four or five years in Dabie Mountain, Wudang Mountain, Lushan Mountain, Maoshan Mountain, Funiu Mountain and many places in Hubei, Jiangsu, Anhui, Henan and Hebei, collecting specimens, conducting some pharmacological experiments and writing down millions of words of investigation and interview records. With this rigorous attitude and tenacious will, Li Shizhen overcame a series of difficulties, such as the hardships involved in the wild mountains, the instability of family life, and the grief of parents' successive deaths. After 18 years' struggle, he finally finished his masterpiece Compendium of Materia Medica in 1578. From the first draft to the final draft, he was used to the "three revisions", and carefully analyzed and studied a large number of collected materials, eliminating the rough and refined, eliminating the true and the false, and constantly improving the accuracy of its classification and the scientific nature of its discussion, thus ensuring that this scientific work has a superior academic level.