The purpose of this thesis is to investigate how modern tragedies could be established and the concept and meaning of Miller`s social tragedy. Traditional views of tragedy assume a hero who is either upper-class or a very intelligent aristocrat, and who violates, because of some personal weakness in his nature, called tragic flaw, the moral values and social regulations. For daring such a challenge, the hero suffers, to prove to audiences that their society and its values are inviolable. Miller, however, refused to adhere to the traditional tragic theory. He wants to write plays in which the average man in the street becomes the tragic protagonist. For Miller a character is tragic when he is ready to sacrifice his life to secure his sense of personal dignity and he believes that the common person knows the feeling of displacement and alienation best. He argues that tragic heroes are defined by their willingness to sacrifice everything in order to maintain their personal dignity-whatever their status in society. A great variety of plots and characters appear in Miller`s social tragedies, yet there are certain thematic concerns which tend to reappear frequently. Examples of some of his more specific concerns would be the importance of the past, issues regarding responsibility and connection, the nature of families, the damage caused by capitalism and materialism, and the law. Miller also tried to use various experimental forms like a memory drama and expression by overcoming or expanding conventional realism. The memory play is his important vehicle for articulating his social visions. He thinks that realism by itself cannot bridge the gap between private and social life because the language of prose, he argues, is the language of our private life, and verse or nonrealistic drama is the medium for dramatizing social forces. The memory plays include Death of a Salesman, After the Fall, A View from the Bridge, A Memory of Two Mondays, and Playing for Time. Here, expressionism has been useful to him for grappling with moral, ethical, and social concerns, as well as breaking down the walls of realism. Miller never sees milieu as destiny, though, like the early realists he is interested in the idea of the stage as an environment, rather than as simply a platform for acting, because he is always concerned with the way the outside world shapes the individual. Important, for Miller, is a life which takes on both individual and social responsibility, trying to make the world a better place. His tragedies, on a general level, create a better society by exploring the demands of morality, and uncovering individual and social needs. He lays emphasis on the harmonious relationship between the individual and society. So he tries to teach his audience certain truth about their own lives. Raising social and moral problems, he writes about sucess and failure, guilt and betrayal, and love and responsibility. We can read his plays as lessons suggesting ways by which we can improve our lives. Miller makes his protagonists accept unpleasant truth about their own lives and overcome them to lead a better life. Meaningful, for his socal tragedy, means a life which takes on both individual and socal responsibilities, and actively participate in trying to make the world a better place.