Traditional folk medicine practices in Korea, China, Japan and Hong Kong - all located in Northeast Asia - are comparable. Since different usage of a medicine may reflect cultural or regional differences, a detailed collation of the folk knowledge of traditional medicine can help to distinguish berween true medical knowledge and superstition. In this first volume of a series of books that will compare the differences and similarities of traditional folk medicine practiced around the world, 200 of the most frequently used medicinal plants in Northeast Asia are selected by the international editorial board to be featured. The folk medical knowledge in each entry includes the botanical and local names of the drug, special processing, the administration method, efficacy in each country, contraindications, and side effects. Also included are the scientific data on their chemistry and pharmacology, with references. All this scientific information should be a valuable asset to medical and research scientists working on the bioactive components of natural products.