Bulbophyllum Thou. is a largest genus in Orchidaceae family and a well-known plant of tropical area. In this study original nucleotide sequence data of matures K (matK) were collected froms 53 species of Bulbophyllum and used to infer the species interrelationship with maximum parsimony and maximum likelihood analysis. Alignment between matK sequences from 53 species of Bulbophyllum was performed, and discovered that the average percentage sequence divergence within Bulbophyllum species was 2.4%, and maximum in-group divergence was 8.8% between Bulbophyllum tenuifolium with Bulbophyllum ovalifolium and Bulbophyllum mutabile. Furthermore, there are 179 mutation sites and 107 information sites in matK sequences, respectively 20.38% and 12.18%. Molecular systematic analysis of matK was revealed that several of the currently recognised sections are consistent in structure with the viewpoint of traditional classification except of sections Desmosanthes, Hirtula and Sestochilus which was contained misplaced elements. In addition presumably, generic status of section Cirrhopetalum cannot longer be supported, as it is deeply embedded within the genus Bulbophyllum and section Desmosanthes is a sister group to Cirrhopetalum with high nodal support.
