Composite mechanisms are composed of simple mechanisms combined into new mechanisms with improved characteristics and functions. Bearing the benefits of easy manufacturing and low cost, they have in use as early as the south-pointing chariot in ancient China, and notably in Watt s steam engine in England of the late eighteenth century. They are fashionable nowadays and will be just as important in the future. After many years of teaching and research, Yan Zhenying has compiled the most important material, arranged the fundamental theories, tabulated tables, and created examples of his own. Composite Mechanisms is neither a handbook nor an encyclopedia; rather, it can serve as a reference book or a textbook for senior and graduate students, engineers, and researchers of mechanical engineering. It is acts as an introduction, a key to the fascinating world of genius. Many ideas remain to be discovered, and problems remain to be solved. Composite Mechanisms stands as a guide, a teacher, and a friend that will accompany you wandering through the wonderland of science and technology.