Based on the previous studies on numerical taxonomy and multilocus enzymes electrophoresis patterns of the 12 rhizobial strains isolated from Shapotou region, the contents of G + C mol%, DNA-DNA relatedness and 16SrDNA sequence of the representative strain were tested. The DNA G + C content of the members of this group ranged from 56.4 to 62.2. The values of DNA-DNA hybridization within the group were above 70%, and relatendness between representative strains of this group and known rhizobial species was below 66.6%. The full-length of 16S rDNA sequence of representative strain N220 was compared with the type strains of all known rhizobia species and related bacteria by the PHLIP version 3.572c composed a unrooted phylogenetic tree, the strain N220, R. galegea, two unnamed rhizobial strains(SH19312, SH22623) and three A-grobacterium strains constituted a branch in this tree. The similarity values of 16S rDNA sequence between strain N220 and other strains in this branch were above 95%.