Usnea jingdongensis from the Ailaoshan Mountain of Southwest China, is described as a new species of Parmeliaceae. It is characterized by the uninflated branches, fistulose axis with pale brown to dark brown loose hyphae, and the absence of pseudocyphellae and soralia. The phylogenetic analysis of the nrDNA ITS sequence data supported the recognition of the species. A key to the eumitrioid Usnea species in China is also provided. Key words: Asia, evolutionary tree, Lecanorales, protocetraric acid, taxonomy.