Dasein,Meitsein,Fallen and Entefremden are the highlights of our living situation of modern human in Heidegger 's sight. We are living in an average everydayness world and equipmental context,therefore have to level ourselves beneath the inauthentically others' world.By analyzing and discussing air extreme sport,this paper believes that when people are hanging in the air in a sudden,all of their experience world and equipmental context would be broken down,furthermore,the strong anxiety and possibility imminent to death on this ...