We present the lexical-semantic net for German "GermaNet" which integrates conceptual ontological information with lexical semantics, within and across word classes. It is compatible with the Princeton WordNet but integrates principlebased modifications on the constructional and organizational level as well as on the level of lexical and conceptual relations. GermaNet includes a new treatment of regular polysemy, artificial concepts and of particle verbs. It furthermore encodes cross-classification and basic syntactic information, constituting an interesting tool in exploring the interaction of syntax and semantics. The development of such a large scale resource is particularly important as German up to now lacks basic online tools for the semantic exploration of very large corpora.