Abstract: The genus Orthodontium of the family Bryaceae is newly reported from Yunnan, China. The O. bilimbatum X. J. Li et D. C. Zhang as a new species, found in the Mt. Meilixueshan, Northwestern Yunnan, China, is described in Latin and illustrated in this paper. It is of main characteristices of (1) the double peristomes being not in well-development, (2) bistratose leaf borders, consisting of 2- 3 rows of elongate-linear thick-walled cells which occur on all leaf margins except for the apices and proximal bases, (3) the cells in middle of leaf 60~ l00 um long and l8~ 24 um wide, (4) opercule short conical without beak on it. The characteristics of the new species are between genera of the Orthodontium and Orthodontopsis. With double peristomes as an important character of Orthodontium on taxonomy, the new taxon should be classified into the genus. In addition, 2, 3 and 4 characters men- tioned above are special in this genus, so a new Section Bilimbatumis proposed. The specics as a holotype of the new section is deposited in Cryptogamic Herbarium, Kunming Institute of Botany,Academia Sinica(HKAS).

Key words: Orthodonlium