Wang Ang wrote a lot of books on medicine. Although he made contribution in the aspects of practicability, circulated dimension, and the popularization and the advancing of medicine, his achievement is mainly focused in the field of methodology of prescription. His book of prescription, Variorum of Medical Recipes, is simple, practical, reasoning, and concentrated on the main points. So, this book can be used as an introduction to prescription, as well as a good reading for prescription methodology.