Abstract: The molecular genetic evaluation of the collected 33germplasm resources in six different geographical populations were analyzed by SRAP molecular marker,in order to provide reference for the comprehensive utilization of Bletilla striata Rchb.f variety resources,in situ conservation and ex situ conservation of wild resources.The results showed that the genetic diversity of Bletilla striata was abundant at the species level.The genetic diversity index of Bletilla striata populations was Ht=0.326 7,Hs=0.235 6,Gst=0.250 6,Nm=1.495 2.These results indicated that there was a mount of gene exchange among the populations,and the genetic variation mainly occurred within the populations.Based on UPGMA,six populations gathered in two clusters.Population structure analysis showed that the best classification result when K=2was used.Mantel test confirmed that genetic distance of species was significantly positive correlated with geographical distance（r=0.624 6;P ＜0.001）.