Many of software designers of CSCL environment have been suffering from complex and subtle educational requirements offered by clients. One of major causes of the problem they face is the lack of shared understanding of collaborative learning. We do not know what design rationale of CSCL environment is and even do not have common vocabulary to describe what the collaborative learning is. In this research, we are aiming at supporting such complex instructional design (ID) process of CSCL environment. To fulfill the aim we have been constructing an ontology to represent CSCL session[1,2]. The ontology will work as both vocabulary to describe the session and design patterns referred to during the instructional design process. To represent learning scenarios using the ontology will facilitate users’ shared understandings and reuse the scenarios. It is useful to store and provide effective learning scenarios as design patterns. As the first step to fulfill our aim, we adopt learning theories as foundation to analyze, design, and develop the learning sessions. The design patterns inspired by the theories provide design rationale for CSCL design.