The International Symposium on the Science and Technology of Mesoscopic Structures was held at Shin-Kohkaido in Nara from November 6-8, 1991. The symposium was sponsored by the International Institute for Advanced Study and partly by Nara Prefecture, Nara City, Nara Convention Bureau, and the Ministry of Education, Science and Culture of Japan, as well as industrial organizations. We would like to acknowledge the support of the symposium by these or­ ganizations. The scope of the symposium was planned by the organizing committee to cover outstanding contributors in the fields of (1) ballistic transport, (2) electron wave­ guides and interference effects, (3) quantum confinement effects, (4) tunneling phenomena, (5) optical nonlinearity, and (6) fabrication technology of meso scopic structures. Twenty-six invited speakers were selected from the United States, Europe, and Japan. In addition twenty-four contributed papers were accepted for presentation at the poster session. These papers are included in the proceedings. We are grateful to the organizing committee, Ms. Y oshiko Kusaki of the Inter­ national Institute for Advanced Study for the secretarial service, and Dr. Nobuya Mori, Osaka University, for his scientific cooperation. Thanks are also due to the authors and the participants for their contributions to a successful symposium.