During our ongoing studies of bambusicolous fungi in southwest China and Thailand, three saprobic pleosporalean taxa were discovered on bamboos in Yunnan Province of China. Occultibambusa hongheensis and Seriascoma bambusae spp. nov. are introduced based on morphological characteristics coupled with multi-locus phylogenetic analyses of combined LSU, SSU, TEF1-α, RPB2 and ITS sequence data. Occultibambusa kunmingensis is also reported from a terrestrial habitat for the first time. Comprehensive descriptions, color photo plates of micromorphology, and a phylogenetic tree showing the placements of these three taxa are provided. In addition, synopsis tables of Occultibambusa and Seriascoma with morphological features are also provided.