In today's world, WWW as a platform to deliver instruction enables e-learning systems to manage a large quantity of different digital content. Teachers contribute their expert knowledge and students contribute their investigation works, tasks, etc. As a consequence of this, the content repository grows with a lot of information. Then, an urgent need exists to retrieve the specific information they will need through e-learning systems. knowledge management is used in e-learning. Users are able to manage and reuse content according to their needs without interoperability problems. However, how to use knowledge management in e-learning. This paper attempts to analyze what must be considered to knowledge management in e-learning.