This volume contains the Proceedings of the "XXIV. Inter nationale Universitatswochen fur Kernphysik" held in Schlad ming, Austria, in February 1985. It consists of the written versions of the lectures (3-4 hours) given at this winter school and includes also most of the seminars (30-50 minutes) presented. In choosing the topic for the 1985 meeting, our aim was to give an account of the present understanding of the nucleon-nucleon as well as nucleon-antinucleon inter actions. This field, which is of definite relevance in nuclear and particle physics, has witnessed a rapid develop ment in recent times both in theory and experiment. New evidence has emerged in the whole range from low to extremely high energies. It was an exciting experience to bring to gether knowledge from the very domains of nuclear and high energy physics as well as to meet the respective researchers. Thanks to the efforts of the lecturers, who did a splendid job in presenting the lectures and in preparing their lecture notes, a comprehensive insight into the hadronic interaction between nucleons and anti-nucleons was achieved. The lecture notes were reconsidered by the authors after the meeting and are now being published in their final form. The seminars mainly dealt with specific topics currently under investiga tion within this rather wide field. We are grateful to all authors for their efforts, as they made it possible to speed up the publication of these proceedings."