Introduction. Business Process Model and Notation (BPMN) is widely used standard for modeling business processes and supported by the Object-Oriented Technology Specification Management Group (OMG). However, the BPMN 2.0 specification is quite lengthy and contains over 500 pages. Item definitions are scattered across different sections of the specification and sometimes conflict. In addition, the structure of elements and their relationships are described in the form of metamodel, but further syntactic rules are defined within the natural language text. The purpose. This article proposes an ontology that formally represents the BPMN specification. The item description is consolidated within the appropriate class, and further explanations are provided in the annotations. The taxonomic structure in an ontology provides navigation through concepts in is-a relationships. Methods. A possible way to organize terminological vocabulary is the construction of ontologies, terminological systems and the creation of terminological data banks. The open source Protégé ontology editor was chosen to form the ontology. The correctness of the resulting terminology is partly ensured by the Reasoner included in Protégé. Results. The ontology of BPMN 2.0 notation can be used in the educational process as reference, as well as to control knowledge. In addition, ontology can be used as tool for solving semantic search problems. A potentially interesting result can also be an automated synthesis procedure based on the proposed ontology of questions for tests in the LMS Moodle system or similar.