Nowadays the collaboration of organizations, systems or services becomes more and more answered in practice. Indeed, organizations try to expand their service, other to satisfy the needs of their customers. Thus, the need to work collaboratively with other partners whether internally or externally becomes trivial. However, process modeling in a collaborative environment becomes heavy because of the diversity of information exchanged and the complexity of shared task. Certainly, the BPMN is the most answered standard for the modeling of business processes, moreover it offers a collaborative diagram that allows to model collaborative processes, but later we will see that its capabilities are very limited. For that, we try in this work to create a collaborative business process modeling language that allows to better model these types of processes and respects some aspects of a collaborative environment. We used the BPMN extension mechanism to create our own language that we named «BPMN4Collaboration».