Based on several field investigations and numerous data references, we analyzed the floristic composition, geographical element, floristic affinity, floristic characteristics and floristic origination of pteridophytes in Naban River Watershed National Nature Reserve in the present paper. The main results are as follows: (1) there are totally 239 fern species, belonging to 90 genera and 43 families in the area. The dominant families are Thelypteridaceae, Pteridaceae, Athyriaceae and Aspidiaceae, and the dominant genera are Pteris, Microlepia, Cyclosorus and Pyrrosia. (2) Floristic analysis reveals that the pteridoflora is of tropical nature, but characterized with conspicuous transition to southern subtropics. It is confirmed that the pteridoflora of Naban River Watershed National Nature Reserve is a part of Tropical Asian pteridoflora, but affected by SinoHimalaya pteridoflora in some extent. (3) On the aspect of geographical connection, the pteridoflora of Naban River Watershed National Nature Reserve has the strongest affinity with Dawei Mountain, followed by Hainan Island and Ailaoshan Mountain Nature Reserve, and has a distant relation with Cangshan Mountain, Jiaozixueshan Mountain and Diaolin Mountain Nature Reserve.