A new poroid fungus in the family Steccherinaceae, Antella tibetica sp. nov., is described from southwest China based on morphology, and phylogenetic analysis. The species was found in the Tibet Autonomous Region of southwest China, growing on angiosperm wood of a low decay stage. It is characterized by an annual growth habit, resupinate basidiocarps with buff yellow to yellowish brown pores, 0.5–1.5 per mm, a dimitic hyphal system composed of clamped generative hyphae and subicular skeletal hyphae encrusted with fine crystals, abundant gloeocystidia that are variable in shape, and oblong-ellipsoid basidiospores. The phylogenetic analysis based on ITS + nLSU rDNA sequences shows that A. tibetica nests in Antella, forming a monophyletic lineage with strong support (100 % BS, 100 % BP, 1.00 BPP). The differences between A. tibetica and other members of the genus are discussed. A key to accepted species of Antella is provided.