Discovery of an appropriate learning object according to the needs and interests of a client is one of the major challenges. Although SCORM presents some approaches for content reusability but efficient searching process is a significant problem yet. Under SCORM definition a learning content is packed as a Sharable Content Object (SCO). Some approaches like Semantic Web and Ontology were proposed for resource searching in the web. In this work, we would introduce ontology for discovering learning objects with emphasizing on the SCO's. Focusing on Learning Objectives is the significant innovation of this work. In this research, we assessed related works and centred our attention on their most significant common concepts. Then, some new concepts were added to complete our proposed ontology.