A new poroid fungus, Nigrofomes submelanoporus, from tropical China, is described and illustrated based on morphological characteristics and phylogenetic analysis. The new species is characterized by perennial, resupinate to effused-reflexed, woody-hard and dark gray to almost black basidiocarps, lacerate dissepiments, a monomitic hyphal system, the presence of cystidioles and hyphal pegs, and broadly ellipsoid basidiospores (4–5.1 × 3.1–4.3 µm). Molecular analysis based on ITS sequences demonstrates the phylogenetic position of the new species in Nigrofomes. The discriminating characteristics between the new species and closely related species are discussed.