Since the beginning of the XX century the dual system interpretation of Marxian theory of value went to meet a series of analytical problems which has questioned its logical soundness. According to many, the theoretical controversy about the “transformation problem” has found a conclusion with the Piero Sraffa publication of Production of commodities by means of commodities. Since the eighties, however, the debate has been opened again by a lot of contributions suggesting a single system approach to the labor theory of value and highlighting the role of “living labor” as the only possible source of new value. The New Interpretation, independently presented and supported by Lipietz, Duménil and Foley, has been then developed in particular by the latter two, but also in Italy some authors have attempted to rehabilitate the Marxian theory of value as labor theory of new value. Since the end of the seventies, Marcello Messori has argued that the first macroeconomic invariance condition had to be reformulated in terms of net product. Few years later, Augusto Graziani has provided a macroeconomic and class interpretation of the Marxian theory of value. Riccardo Bellofiore, at the end of the eighties, has developed Graziani’s insights and has reinterpreted the Marxian theory of value as a monetary labor theory of value. Stefano Perri, after reaching the same conclusion of New Interpretation, has developed in formal terms the method of comparison – introduced by Marx – to show how the Sraffian price system must be reformulated if it wants take into account the capital valorization process. Finally, following the Dario Preti’s “discovery” about the presence of the labor theory of new value inside Production of commodities, Giancarlo Gozzi and Giorgio Gattei have emphasized the particular numeraire condition which has to be assumed to solve the Sraffa’s price system and, at the same time, to get back an absolut conception of value within his theoretical framework. This work has the aim of proposing a critical survey of the most important contributions which have argued the need of interpreting the Marxian labor theory of value as a labor theory of new value, drawing attention on the Italian economists which have stressed the “living labor” as the fundamental category to restate the Marxian theory of value and his analytical soundness.