The purpose of this study is to examine the foundation on which German expressionist dance had been formed a cultural movement. It also aims to identify the relationship between expressionist dance mainly focusing on describing one's inner self and post-modern dance in the US, which has allowed classical dance to develop as a part pop culture by demolishing artistic barriers. What expressionist dance has in common with post-modern dance is that they both place emphasis on the human body. Both view the human body as a tool, and in both the human body is used realistically and not exaggerated. Neither plot nor gestures are the main media used to convey emotions or feelings. Expressionists put priority on the alignment between body movements on stage and our gestures in life. Without any special techniques, they seek to express inner feelings and thoughts to the audience through body gestures. For instance, in the works of Yvonne Rainier, an American choreographer, the smooth and consistent description of weight seems to be the fundamental heritage of expressionism, but her dance is more unique and tries to directly involve the audience's interests. In addition, Merce Cunningham, one of the founders of American modern dance, has tried to integrate what's typical of expressionism with the atmosphere of something anarchical in his works, and to outwardly express what's happening inside the mind. He has largely adopted the choreography of expressionists but his major concern was not on choreography itself but the expression of basic body movements. Clearly, although these two dancing trends emerged against different cultural backgrounds, German expressionists have influenced the American post-modern dance, and continue to influence cultural movements. Therefore, in the contemporary art world where people believe nothing is new, the pursuit of genuine beauty through our bodies should be emphasized rather than focusing on debates on the specific division of genres such as expressionism, modern dance or post-modern dance.