This manuscript is the final result of the project supported by the National Social Science Fund of China, The Relationship between Hu and Han and Cultural Identity in the Tang Dynasty Seen from Epitaphs (Approval No.: 09BZS038; concluded in June 2015 ). The main content is as follows: This book selects the individual cases of Qangqil-Tuoba, Va zha and Sogdiana as examples, combines the epitaph materials with the handed down documents, and makes a more in-depth research on the activities of foreign ethnic groups in the Han Region of the Central Plains in the Tang Dynasty the relationship between Hu and Han reflected on the basis of fully referring to the existing research results of Chinese and foreign counterparts, in order to explain various development trends of multiple ethnic groups in the Tang Dynasty and their causal relations, so as to reflect the main trend of the era.