From the early fourth century, there occurred in China a large-scale "geographic exchange", in which a multitude of geographers and geographic Works emerged. The most outstanding of all the geographer was Li Daoyuan, and the most outstanding of all geographic works was his "Notes on Book of Waterways". Li was not only a celebrated scholar, but also a patriot, and "Notes on Book of Waterways" not only a geographic masterpiece, but also a patriotic work.