To have a sustainable competitive advantage, an organization should realize how to create, distribute and utilize knowledge through an organization and how attach it to organizational process. Another important thing is a manager should know what kind of knowledge they should seek to enhance organizational activity to get sustainable competitive advantage. In this paper, I go through literature review to investigate more the importance of knowledge management in the respect of competitive advantage. I start with an introduction and we will move on the next stage, which will be knowledge as a basis of competitive advantage. The third part would be the importance of knowledge management. Knowledge management and competitive advantage, knowledge strategies for survival, knowledge integration capabilities and IS support of organizational competencies would be other issues which will be considered in this paper. Keywords : knowledge management , competitive advantages.