In a society with virtually all phases of the economy subject to planning an interest in regional economic planning almost inevitably arises. Such an interest has been evident in the USSR since the early 1920s, although not always to the same degree. Out of this interest evolved the notion of the economic complex, broadly conceived as a regional grouping of integrated economic activities. Inasmuch as these complexes were frequently thought of as geographic entities, the expression “territorial-production complex” (territorial'no-proizvodstvennyi kompleks), as well as some essentially synonymous terms, came into use. Interpretations vary somewhat, but, to judge from the frequency of reference to the concept in the professional journals of the geographers, economists, and planners, the idea seems to be a basic one among those concerned with regional planning.