The line between lifestyle and social identity in sociology is based on the distinction between traditional and modern society. In traditional societies lifestyle and social identity are based on their related features. However, in this regard, in terms of time precedence, modern societies mainly offer two different answers, each based on different theoretical approaches. The first and the older approach focuses on productive activities and one's place in the social identity constructive system; and the second which is the newer approach, considers one’s consumption behavior as the basis for social identity. The first approach is related to the concept of social class and the second approach is summed up in the concept of lifestyle. Methodology of the present research is based on Delphi technique focused on the urban middle -class youth who are 15 to 29 years old and the research partners are selected from university professors. The present study uses three basic indices from the available indicators and they have been changed to be applicable for this analysis. The aim of this study is to provide new criteria based on novel social groupings considering recent decade lifestyle that indicates the boundaries of identity. Manuscript profile