Liu Xun is a professor at Beijing Language and Culture University, part-time professor at China People''s University and Beijing University of Foreign Languages, member of the Hanban Expert Advisory Committee for Teaching Chinese as a Second Language, board member of World Chinese Teaching Association and consultant of Chinese teaching for the New York State Department of Education. His research focuses on Teaching Chinese as a Foreign Language, Second Language Acquisition, teaching material development, teachers''training, etc. He once assumed the main responsibility in the design of the first set of HSK. He has compiled and co-compiled TCFL textbooks such as Practical Chinese Reader (1-4), Chinese Textbook for Children, Elementary Chinese, One Hundred Lessons on Communicative Chinese, etc, and has published monographs such as Introduction to Chinese as a Foreign Language Pedagogy, Introduction to Teaching Chinese as a Foreign Language, Brief Introduction to Teaching Chinese as a Seco