Reflection on the Theory of Surplus Value of Karl Marx

We have analyzed the limit of the theory of surplus value of Karl Marx in this paper, and concluded as follows: the increase and decrease of the quantity of surplus value can not be fully explained by the social labor time; it is necessary to differentiate social surplus and surplus value since the circulation field can not be neglected in the production of social surplus; the position of materialized labor and human labor must be particularly analyzed, and exploitation is not necessarily the only source of social surplus.