This volume contains the proceedings of the Fourteenth Thniguchi Symposium on the Theory of Condensed Matter, which was held from November 10 to 14, 1991, at the Shima Kanko Hotel, Shima, Japan. The topic of the symposium was Physics 0/ Mesoscopic Systems. Mesoscopic systems have been developed band in band with the recent progress in nanotechnology and are the melting pot of basic science and technology. In nanostructures, the quantum effect of the electron wave manifests itself because of the limited dimensionality of the structure. The most typical features of these structures are the discreteness of the energy spectrum and the interference effect of electron waves, which have led to various fascinating phenomena. The purpose of this symposium was to discuss the latest developments in mesoscopic systems, especially transport phenomena, from the viewpoint of basic physics. This volume starts with an introduction to the field of mesoscopic systems together with the paper by Prof. R. Kubo, who was the first to note the existence of particular features of discrete energy levels in small metallic particles. In Part II the electronic states of quantum dots and the conductance through them are discussed. Tunneling via small structures and junctions is studied in Part ill.