Abstract: AIMTo design a pair of allele-specific diagnostic primers for authenticating D.devonianum from other Dendrobium species by PCR. METHODSBased on rDNA ITS sequences database of D.devonianum and other Dendrobium species of Fengdous and Huangcaos, an allele-specific diagnostic primer pair, JB-Chiban-01S and JB-Chiban-01X, was designed. Diagnostic PCRs were performed using the primer pair with the total DNAs of the original plants of 38 Dendrobium species as templates. RESULTSWhen the annealing temperature was raised to 58℃, only the template DNA of D.devonianum could be amplified whereas the diagnostic PCR of the rest 37 species were all negative. The diagnostic PCR have been repeated many times and played an important role in authenticating D.devonianum in China. CONCLUSIONThe diagnostic PCRs can authenticate D.devonianum from other Dendrobium species efficiently. Compared with the anthentication method by sequencing DNA fragments, the allele-specific diagnostic PCR was not only simple and timesaving but also practical and effective.