Topic Maps and RDF are two independently developed paradigms and standards for the representation, interchange, and exploitation of model-based data on the web. Each paradigm has established its own user communities. Each of the standards allows data to be represented as a graph with nodes and labeled arcs which can be serialized in one or more XML- or SGML-based syntaxes. However, the two data models have significant conceptual differences. A central goal of both paradigms is to define an interchangeable format for the exchange of knowledge on the Web. In order to prevent a partition of the Web into collections of incompatible resources, it is reasonable to seek ways for integration of Topic Maps with RDF. A first step is made by representing Topic Map information as RDF information and thus allowing Topic Map information to be queried by an RDF-aware infrastructure. To achieve this goal, we map a Topic Map graph model to the RDF graph model. All information from the Topic Map is preserved, such that the mapping is reversible. The mapping is performed by modeling the graph features of a Topic Map graph model with an RDF graph. The result of the mapping is an RDF-based internal representation of Topic Maps data that can be queried as an RDF source by an RDF-aware query processor.