Arthur Miller plays an important role in American literature. His works have a great influence on American literature afterWorld War Ⅱ.Willy Loman is the symbol of modern American man. His living state is typical during that time in America. This paperstarts with a survey of Willy’s two dreams-his children can own big future; he can own big business. In the second part, the author contrasts Willy’s unreal dreams with the reality, through this comparison, aims at analyzing the sad elements of Willy’s life, exploring thesource of his sadness. Willy is one convict of American dream. He is influenced greatly by the American cultural mainstream. As an individual drowning in the harsh world, he cannot grasp his own fate by himself.