The upcoming digitalisation and emergence of complex data structures are increasingly in need of visualisation and interaction concepts, which offer users a suitable explorative as well as manipulative access to a high-density information space. This thesis addresses the problem with a systematic investigation of novel interaction concepts in complex graph systems and combines mobile devices with a high-resolution wall-sized display, which shows the overview of the scene. Based on this device constellation and the application context with its underlying graph tasks, the thesis classifies functional roles of the mobile display to the context display. Subsequently it presents tangible mobile graph tools in a structured design space. The spatial interaction space in front of the wall-sized display provides a virtual information space in which the mobile device creates an immediate spatial relationship to the graph visualisation. This enables individual encoded see-through views as well as selection and manipulation techniques beside the on-screen interactions of the context display itself. The comprehensive repertoire of tangible graph tools forms the main part of the thesis. As a last step the prototypical implementation demonstrates the technological feasibility of parts of the concepts.