The International Union of Theoretical and Applied Mechanics (IUTAM) initiated and sponsored an International Symposium on Optimization of Mechanical Systems held in 1995 in Stuttgart, Germany. The Symposium was intended to bring together scientists working in different fields of optimization to exchange ideas and to discuss new trends with special emphasis on multi body systems. A Scientific Committee was appointed by the Bureau of IUTAM with the following members: S. Arimoto (Japan) EL. Chernousko (Russia) M. Geradin (Belgium) E.J. Haug (U.S.A.) C.A.M. Soares (Portugal) N. Olhoff (Denmark) W.O. Schiehlen (Germany, Chairman) K. Schittkowski (Germany) R.S. Sharp (U.K.) W. Stadler (U.S.A.) H.-B. Zhao (China) This committee selected