RÉSUMÉ
Objective: To identify and preliminarily analyze the plants of Marsdenia R. Br. and its related species by ITS2 and rbcL sequences. Methods: The ITS2 and rbcL regions were amplified and sequenced directly. The sequence was manually calibrated using CodonCode Aligner, and splited and jointed by Contig software. The genetic distance analysis was carried out by MEGA 4.0 and the phylogenetic tree was constructed using the Neighbor-joining method. Results: The samples analyzed were well identified by ITS2 and rbcL sequences, and the authentication ability of ITS2 was superior to rbcL. The genetic relationship among the plants of Marsdenia R. Br., Dregea E. Mey., and Gymnema R. Br. was very close. Conclusion: ITS2 and rbcL sequences could distinguish Marsdenia R. Br. species very well, and the authentication ability of ITS2 is superior to rbcL. The preliminary studies suggest that the Dregea E. Mey. and Gymnema R. Br. should be classified into genus Marsdenia R. Br.