Being fragmentary in nature, fossil fungi lack characteristic features that are diagnostic of extant taxa. Except for some distinctive Tertiary forms, most of the fossil fungal remains can seldom be compared with modern taxa hampering their classification under the Natural System. Problems concerning the nomenclature and classifi cation of fossil fungi have been discussed by various workers from time to time. Th ey argue that assigning most of the fossil forms a modern name will lead to a taxonomic confusion and it will therefore be more convenient as well as logical to describe the fragmentary fossils as form genera which are described on the basis of morphological characters only. Under this scheme, fossils are given artifi cial generic and specifi c names and wherever possible their affi nities with extant taxa are suggested. Th is chapter provides a brief introduction to the conventional systems of classifi cation proposed for fossil fungal spores and fruiting bodies. Diagnostic characters of these form genera are also given.