Li Shih-chen, author of the most important medical work of ancient China, made immeasurable contributions to the health of the people. His masterpiece, The Compendium of Materia Medica, is not only a summing up of the pharmacological knowledge accumulated in the two thousand years before his time but also a prototype of the science of plant morphology. In his book we see clearly that his methods of observing and experimenting with drugs made through biological or chemical processes, are very similar to methods used in modern science. Like many other scientific achievements, Li Shih-chen's work has only now, when the people have taken over the direction of their own lives, received the honour and consideration it deserves. In the past ten years, the people's government of China has begun paying particular attention to the centuries-old Chinese art of healing, and has called upon the medical profession to study and develop this art. In this development, Li Shih-chen's work has a special significance. Less than four hundred years have passed since Li Shih-chen's death. Historical records give us scanty information about his life and work, but what there is, is clear and succinct. This book is based mainly on three historical documents: the memorial Shih-chen's eldest son, Li Chien-chung, wrote to the Emperor when he submitted his father's book to the imperial court, the Biography of Li Shih-chen found in the History of the Ming Dynasty, and the Biography of Li Shih-chen by Ku Ching-hsing. Before he wrote this book, the author visited Li Shih-chen's home town, Chichow, and saw his grave, investigated the ruins of his house, and took down the epitaphs engraved on his tombstone. Tales about the life of Li Shih-chen are still circulating among the people in Chichow, and these tales have given the author important material with which to fill in the gaps in the daily life of Li Shih-chen. All documents, epitaphs and tales point to one unmistakable fact: Li Shih-chen was a hard-working man of courage and firm principles who devoted his entire life to his ideal, the creation of The Compendium of Materia Medica. All sources affirm his outstanding ability as a doctor and his noble humanism. The above-mentioned material has provided the skeleton of the story of Li Shih-chen's life. The author has filled in the details through literary imagination.