During a survey of microfungi associated with palms from karst formations, three novel ascomycetes were found from decaying petioles of Trachycarpus fortunei (Arecaceae) in Guizhou, China. Multi-gene phylogenetic analyses based on a combined SSU, ITS, LSU, RPB2 and TEF1α sequence data showed that these collections were affiliated to Brunneofusispora and Neooccultibambusa in the family Occultibambusaceae. A new species Brunneofusispora inclinatiostiola is introduced. It is phylogenetically close to B. clematidis but represents a distinct lineage. Morphologically, it differs from the latter in having immersed ascomata with eccentric, periphysate ostiole and smaller ascospores. Morpho-phylogenetic evidence also revealed two new Neooccultibambusa species, N.kaiyangensis and N. trachycarpi. Together with the generic type N. chiangraiensis, they formed a distinct lineage within the genus Neooccultibambusa. Three novel palmicolous fungi of Occultibambusaceae are described, illustrated and notes on their identification are provided. The ecological significance of the new taxa and the phylogenetic relationship of genera in Occultibambusaceae is discussed.