This volume studies the development of Marxian value theory in a modernised context. The controversy about Marx's value theory is now in its third stage. The first stage was marked by Bohm-Bawerk, and the second by Samuelson soon after the World War II. In this second stage, the basic results in Marx's economics were examined and formulated by Okishio and Morishima-Seton in the Leontief economy case. The third stage was opened by Morishima, who developed the Marxian theory of value on the ba~is of von Neumann's theory. In Chapters I through IV, a concise but comprehensive overview of the pOints in Marx's value theory is presented from the Leontief to von Neumann economy cases. Based on the above, the two subjects, namely, the reduction of skilled labour and heterogeneous labour and the Marxian theory of differential rent, are developed in Chapters V and VI respectively. These topics, especially the reduction problem, seem not to have been duly discussed in other literature. The main concern of our discussion, in Chapters I through V in particular, is the so-called fundamental Marxian theorem and the dual dualities, i.e., the duality of price and quanti~y systems on the basis of the duality of value and price. Th. ~uthor also tried to shed light on superhistorical aspects of Marxian vaiue theory, which ought to give a clue to the insight of the commodity production in general. The author acknowledges thanks to Professors S.Koshimura, A.