Two main models exist for graph data. Resource Description Framework (RDF), a recommandation of the W3C for the representation of data exchange on the Web, relies on a formal semantic that allows reasoning processes. The second model, usually called Property Graph, natively allows to attach metadata to graph edges. A reconciliation of the two models would allow to take advantage of the strengths of the two models, and to mutualize scientific results and technical tools provided for these models. This PhD objectives are to define a semantic interoperability model between RDF graphs and Property Graphs.