The genus Dendrobium one of the largest genera in the Orchidaceae, includes more than 1148 species, and enormous morphological diversification has hindered the establishment of consistent classification systems covering all major groups of this genus, and 2nd orchids after Bulbophyllum orchids (Bulbophyllum) (Leitch et al., 2009). Southeast Asia can be considered as the homeland of Dendrobium with more than hundreds of species, particularly in Vietnam has more than 100 species (Tran Hop, 1998; Nguyen Xuan Linh, 2002; Averyanov, 2004; Duong Duc Huyen, 2007), and they are widely distributed across the regions of the country.