The volume of proceedings of the Xth International Seminar on High Energy Physics, Relativistic Nuclear Physics and Quantum Chromodynamics brings together reports from the major experimental collaborations at JINR, Fermilab, Brookhaven, SATURNE, Orsay, GSI Darmstadt, Riken Cyclotron Lab. KEK, SLAC, Novosibirsk, MIT Bates, IHEP USSR and summaries of the major theoretical and experimental advances made in relativistic and nuclear physics over the last two years. The focus of the volume is upon relativistic nuclear physics, but the coverage of topics is sufficiently comprehensive to include many important results of cumulative reactions, polarization phenomena in nuclear physics, non nucleon degrees of freedom in nuclei.