Dendrobium anosmum Lindl. var. semialba has variants of flower shapes. Currently, it has high economic value and is favored on the market. In this study, the genetic relationship of Dendrobium anosmum Lindl. var. semialba species was determined based on the analysis of chloroplast matK, rbcL gene sequences. The matK and rbcL genes of twelve species were amplified and their DNA sequenced. These DNA sequences were compared, calculated genetic distance and constructed phylogenetic tree. The results showed that 100% of samples were amplified and sequenced successfully. The analysis of matK sequences showed that 12 species had very high genetic similarity with the low genetic distance of 0 - 0.001; the nucleotide sequences were almost unchanged except for one variable nucleotide position in TB1 and TB1 was in a separate branch of the phylogenetic tree. The analysis of rbcL sequences showed that all species had a low genetic distance of 0 - 0.012 and had 7 mutant positions in nucleotide sequences of TB1 and TB5. These species were in a separate branch of the phylogenetic tree while the other species were grouped in the other branch of the phylogenetic tree. The study provided a reliable molecular database of the Dendrobium anosmum Lindl. var. semialba for identification, classification, biodiversity assessment and conservation of genetic resources.