The knowledge transmitting process from the author to learners does not require only the providing of a simple learning content, but also a set of information about the content (metadata) to ensure an accurate learning process. In addition, the huge amount of educational material exists in a distance learning environment usually confuses learners and does not help to choose the pertinent content for each learner. In the field of E-Learning, the Semantic Web is considered as a promising technology to make the educational content easily accessible and interpretable by software agents. Moreover, it allows communication according to a semantic basis between human agents and machines. In this paper, we propose an ontological approach for the organization of courses around small pieces of semantically annotated learning objects. This annotation of learning content facilitates the organization and understanding of these contents by the machine, and accelerates the delivery of relevant documents in time. In our designed approach, the teacher achieves a main task, he creates the learning content and provides all the necessary information for the annotation of this content, these annotations will play the main role to choose and adapt the relevant contents for each learner.