Abstract:Abstract： Six populations of Atractylodes DC. (Compositae) were used to analyze their chromosome number and karyotype by applying root tip squash method. The results showed that chromosome number in all six populations of Atractylodes spp. was 2n = 24 and the karyotype formulas were as follows: Baokang population 2n=2x=10m+12sm+2st, Shangluo population 2n=2x=14m+10sm, Yuexi population 2n=2x=12m+12sm, Yingshan population 2n=2x=14m+10sm, Xinyang population 2n=2x=14m+8sm+2st, Shennongjia population 2n=2x=8m+10sm+4st. All of karyotypes for the investigated populations were 2B type but Yingshan population with 2A type, which showed that Yingshan population plant belongs to a relatively primitive type and relatively ancient or the primitive plant in evolutionary processes of Atractylodes. According to the dendrogram of Q analysis and karyotype analysis of Atractylodes plant, Yingshan and Shangluo population plant was clustered into one sub-subgroup, whose centromere karyotypes were same, and Xinyang population plant which belongs to A. chinensis and the former two population plant was clustered into one subgroup, and Baokang and Yuexi population plant which belong to southern A. lancea into another subgroup. The result don’t support A. lancea subsp. Luotianensis treated as a separate new subspecies and Yingshan population plant should be A. chinensis plant, but support northern A. chinensis is a new subspecies of A. lancea. The results also showed that there is distance relationship between ShenNongjia population and other five ones. This may relate to its high altitude and complex habitats so that ShenNongjia population plants have less gene exchange with them.