Four species in genus Dioscorea (D.sinoparviflora C.T.Ting.,D.zingiberensis C.H Wright.,D.bulbifera L.,D.polystachya Turczaninow),22 taxa were amplified and sequenced the characteristic of psbA-trnH sequence.The length of D.sinoparviflora C.T.Ting.,D.zingiberensis C.H Wright.,D.bulbifera L.and D.polystachya Turczaninow fragments were 589~593 bp,575~599 bp,372 bp and 355~368 bp,respectively.According to the Bayesian phylogenetic tree,the psbA-trnH fragments couldn’t identify the intraspecific and interspecific species successfully.D.sinoparviflora C.T.Ting.and D.zingiberensis C.H Wright.are also not distinguishable.We suppose the evolution of Dioscorea species may be related with artificial domestication.D.bulbifera L.is close to cultivated Dioscorea species.