Researchers who supported the idea of critical theory based their argument on the assumption that there is always a need for criticism in order to promote changes in society. The ultimate goal of critical theory, rather than predicting, explaining, or understanding social phenomenon, is to point out problems and pushing the decision of transformation. Critical theory assumed that the phenomenon is already existed and the inequality can only be addressed by reorganizing the society. This theory is inherently influenced by Marxism and the analytical ideas of Karl Marx. Although the researching process still involves the action of observing, analyzing, but the core idea of critical theory, as its name suggested, is to pursue changes through criticizing. There are six key concepts of this theory: text, meaning, culture, polysemy, hegemony, and ideology. It is because of its diversity that critical theory has very high applicability in the field of social studies and communication. This article aims to present an overview of the development history of critical theory and one of its outstanding applications – reader response theory.