Abstract: This study was designed to establish a multiplex allele-specific polymerase chain reaction method for simultaneous identification of Dendrobium huoshanense, D. officinale and D. devonianum, which may resolve identification problems of caulis dendrobii. Internal transcribed spacer sequences and trnL-trnF sequences of the Dendrobium species were aligned by BioEdit software, then specific SNPs of the three species were analyzed for designing allele-specific primers and the multiplex allele-specific PCR reaction system was established. The different origin of Dendrobium huoshanense, D. officinale and D. devonianum was amplified and identified by the sizes of respective band. The results showed that 584 bp, 397 bp and 211 bp bands could be amplified by D. devonianum, Dendrobium officinale and Dendrobium huoshanense respectively, when the annealing temperature was 61 ℃ and the number of cycles was 35. The limit of detection (LOD) of D. devonianum and D. huoshanense were both 1.2 ng, while D. officinale was low than 0.24 ng. The detection limit of adulterates in D. devonianum, D. devonianum and D. huoshanense mixture sample was 1%, 1% and 5% respectively. This result suggests that the method of multiplex allele-specific PCR is useful to identify D. huoshanense, D. officinale and D. devonianum is accurate and specific.