The Preceedings are based on the papers presented at the IFIP Technical Conference on Optimization Held in Novosibirsk, July 1-7,1974. The Conference was organized by the IFIP Technical Committee on Optimization (TC-7) and by the Academy of Sciences of USSR. The Conference was devoted to a discussion of the following topics: Theory of Differential Games, Mathmatical Programming and Numerical Algorithms, Optimal Control, System Modelling and Identification. The papers given at the Conference refleted an active progress that had been made in the above mentioned areas and an increasing interest of specialists in optimization in the problems of economy and the environment. The International Program Committee consisted of: L.S. Pontrjagin, G.I. Marchuck(USSR), Chairman, A.V. Balakrishnan(USA), J.L. Lions (France), J. Stoer (West Germany), P.Conti(Italy), K. Yajima (Japan), and S.Olech (Poland).