Abstract: It has become an important practical issue for contemporary Western theorists to reinterpret Marx’s proletarian theory combining the changing of the working class. From the perspective of labor movement, Hart and Negri reconstruct Marx’s political image to provide the theoretical basis for the new revolutionary subject relied on Grundrisse. Based on the positivist methodology, Raymond Aron deconstructs the legitimacy of proletariat class, which leads Marx’s theory to myth. Although their analysis partly hits the new changes of working class, they all have flaws. In Marx’s theory, proletariat is the unity of reality and construction, a concept filled with dynamic, complexity and openness. Only in the overall context of Marx’s pursuit of human liberation, can we deeply understand the true meaning of Marx’s proletarian theory.