This paper provides a survey on the development of exploitation theory in mathematical Marxian economics, by overviewing the main controversies on the proper definition of exploitation since the contribution of Okishio (1963). It begins to introduce and examine the robustness and the economic implications of the debates on Fundamental Marxian Theorem developed mainly in 70s and 80s, and then examines the property relation theory of exploitation by Roemer (1982). Then, it introduces the recent new trend of exploitation theory initiated by Vrousalis (2013) and Wright (2000), and examines its economic implications by introducing a simple economic model. It also introduces and comments on the recent axiomatic studies of exploitation by focussing on Veneziani and Yoshihara (2013a).