This paper presents an ontology-based approach for the design of a Collaborative Business Process model (CBP). The study is part of a model driven engineering approach of mediation information systems. We developed a Knowledge-Based System (KBS), which is composed of three main parts: knowledge gathering, knowledge representation & reasoning, and collaborative business process modeling. The knowledge gathering part starts from a high abstraction level where knowledge from business partners is captured. As a result a Collaboration Ontology (CO) is defined in order to provide a structure to store and use the captured knowledge. In parallel, we try to reuse generic existing knowledge about business processes from the MIT Process Handbook repository. This result in a Collaboration Process Ontology (CPO) described in this paper. The relationship between concepts of both CO and CPO are also described in order to introduce a justification to the set of transformation rules (not described in this article) that are used in the full approach in order to extract knowledge to build the CBP model.