Abstract: The megaspores and microspores of four species of Selaginellaceae — Selaginella bomiensis Ching et S.K.Wu, S. megaphylla Baker, S. mutensis Ching and S. nummularifolia Ching —from Xizang (Tibet) were observed for morphological features under light microscopy and scanning electron microscopy (SEM). The SEM studies showed complex ornamentation on the surface and distinct differences in the four species. The tool may be an important basis for the identification of species and contribute to the materials for systematics study and palynology of Selaginellaceae.Spore morphology of the four Selaginella is covered in detail.