William W. Rockhill was a well-known United States diplomat in the late Qing dynasty. In the early 20th century, he was the United States Ambassador to China. Meanwhile, he was also a famous adventurer, sinologist and Tibetologist. He left the world with numerous works on sinological and Tibetological studies. He not only was an important decision-maker of the American policy towards China (on Tibet-related issues), but also an active participant and practitioner of American relations with China (on Tibet-related issues). In light of Rockhill’s significant role in the diplomatic history of the United States and the history of Sino-U.S. relations and his academic reputation in both sinology and Tibetology, the historical documents and materials that he left have great academic values. Selected Documents Relating to Tibet from William W. Rockhill Papers systematically arranged and introduced Rockhill’s research on and travels to Tibet. It sorted out numerous documents on Tibet-related issues among which there are precious documents of different kinds such as letters, briefings, archives, etc. They are references of high values to readers who aim to understand the policies of the United States to China (on Tibet-related issues) in late Qing dynasty.