The main concern of this study is that, what is the role of methodological rotation of positivism to POST-POSITIVISM in transforming the concept of ideology in discourse? In fact, methodology with removal of desired appearances about the two concepts of ideology and discourse tries to address fundamental changes of internal mechanisms and methodological in order to be understood the conceptual evolution appropriately. While, majority of political analysts attribute the conceptual evolutions to objective and external evolutions and consider poor performance of ideological governments as the main reason for this paradigmatic evolution in the twentieth century, it seems that instead of dealing with fruits and results of performances it should be paid more attention to the origins and methodological foundations. Ideology is the product of the rule positivism. Minded dogmatism and dogma, unchangeable, in human, all of the time and place are the main characteristics of ideological states which are actually and directly influenced by the approach of positivism. The concept of discourse of the rule product is POST-POSITIVISM approach. Identities fluid, opaque and flexible rules, local, related to such time and place as discourse characteristics are quite significantly influenced by interpretation methods.