Two fungal strains were isolated from submerged decaying woods in the freshwater habitats, which are characterized by cylindrical, septate, verrucose, brown conidia, composed of four vertical columns of cells, 3-septate in each column, with four appendages at the base which are slightly tapering toward the apex and each with 5–10-septate. Multigene phylogenetic analyses of combined ITS, LSU, and SSU sequences data showed that the two isolates clustered into a separated clade in Tetraploa. Herein, we report it as a new hyphomycetous species, Tetraploa lignicola. The descriptions, illustrations, and a phylogenetic tree show the placement of T. lignicola, the comparisons between the new species and other morphologically similar taxa in Tetraploa are also provided.