According to different explanations of competitive advantage source in classic literatures,the theory is classified into such six schools as industrial structure-based view,resource-based view,competence-based view,dynamic competence view,knowledge view and behavior view,then theoretical hypothesis and main views of each school are generally summarized and commented.Based on this and according to author's understanding of competitive advantage,this paper points out thinking and conclusion about the source of competitive advantage and sustainable competitive advantage from the starting point of storage flow and circulation flow.