The Third International (Kiev) Conference on Plasma Theory took place at Trieste (Italy) from 5 to 9 April 1977. As is well known, the two previous Conferences on Plasma Theory, organized by the Ukrainian SSR and the USSR Academies of Sciences and supported by the International Union of Pure and Applied Physics, were held in 1971 and 1974 at the Institute for Theoretical Physics of the Academy of Sciences of the Ukrainian SSR in Kiev. The main purpose of the International Kiev Conferences on Plasma Theory is the discussion of problems of plasma physics, which are basic for such scientific and technical problems as controlled thermonuclear fusion, magnetohydrodynamic conversion of thermal into electric energy, creation of new radiowave sources, conquest of space, etc.