This volume contains the Proceedings of the 17th Workshop of the INFN ELOISATRON Project on "QCD at 200 TeV", held at the "Ettore Majorana" Centre for Scientific Culture, EMCSC, Erice, Trapani, Italy, in the period 11-17 June 1991. The new multi-Te V frontiers of Subnuclear Physics are no more beyond our imagination. A conceptual design of the highest energy (100+100 TeV) proton-proton collider -the ELOISA TRON -already exists. Intensive R&D studies are on the go to develop the most promising and innovative detector technologies for the highest energy and luminosity. QCD (Quantum Chromo-Dynamics) will be the theory to describe the expected Physics scenario of future S upercolliders. The purpose of the Workshop was therefore to review the recent status of QCD in High Energy interactions and to discuss the novel aspects of Perturbative and Non- Perturbative QCD with special emphasis on future experimental studies at Super-High Energy Colliders, up to the 200 Te V limit. The topics were: * Classical QCD: particle multiplication, multiplicities and spectra, jet profiles, coherence effects, etc.* Hadron interaction cross-sections and structure functions at Super-High Energies, small-x behaviour, QCD Pomeron, "hot spots". * QCD fragmentation models, present and future. * Artificial neural networks in High Energy Physics. * New theoretical aspects of QCD at Super-High Energies (instanton-induced large cross- sections, baryon number violation and peculiar multi-quark production events, etc.).
