One of the principal concerns of Iranian organizations’ managers is why knowledge management projects don't realize with success and lead to failure in Iran. This is one of the matters that discussed in this paper. As regards, implementation of knowledge management consider as a change in an organization, so, change management is a potential answers considered in this paper. The approach on knowledge management in an organization is the second potential answer considered in this paper. The objective of this paper is to show the importance of change management in implementation of knowledge management and present a distinct approach and classification of methods and techniques of knowledge management. This paper tries to answer questions with a qualitative-descriptive methodology by phenomenological way. The failure factors in knowledge management will be studied by inductive reasoning. The results show two important aspects: a new classification in Knowledge Management, which will be proposed in seven different domains, and Change Management is important step in implementation of Knowledge Management process.