This book is a collection of selected papers presented at the First Interna- ti onal Conference on the Structure of Surfaces (ICSOS-1). ICSOS-1 was hel d on the Berkeley campus of the University of California during August 13-16, 1984. The International Organizing Committee members were: S.Y. Tong (Chairman), M.A. Van Hove (Vice-Chairman), D.A. King (Secretary), D.J. Chadi (Treasurer), D.L. Adams, A.M. Bradshaw, M.J. Cardillo, J.E. Demuth, J. Eckert, G. Ertl, B.I. Lundqvist, J.B. Pendry, Y. Petroff, M. Simonetta, J.R. Smith, G.A. Somorjai, J. Stohr, R. Ueda, and X.D. Xie. The series of ICSOS...