Previously, he studied at the University of Tokyo in 1998-2000, and served as visiting fellow at the Center for International Security and Cooperation at Stanford University in 2005, and also as visiting scholar at the Fairbank Center for East Asian Research at Harvard University in 2005-06. His research interests include international relations theory and East Asian studies. Dr. Yu received his Ph.D., M.A. and B.A. from Peking University.