The article with regard to subjects such as methodology and epistemology, tries to explain the methodological aspects of political science from Post- Modern approach. When we talk about the methodology from the Post- Modern view point, deconstructionisn is the only term which one can imagine that Post-Modern approach and analysis applies in political science, This approach has a different view to the case of science, especially, political science and emphasizes on relativism which purifies in familiar margins from science and prepares the suitable conditions for an impartial analysis regarding political problems in Post-Modern world.