AbstractBased on investigation of rhizobial resources of Shandong Province, 102 phenotypic features of 31 fast growing rhizobia strains and 34 reference strains were analyzed and numerically classified. The results revealed huge diversity among strains isolated from different places. Strains with the same geographic resources and the same hosts differed in carbon and nitrogen nutrient utilization, resistance to antibiotics, and tolerance to salt, alkali and chemical dye. Thirty two percent of strains could resist 300 μg/mL Neomycin and 39 percent of strains could resist 300 μg/mL Penicillin and Jiemycin. Two strains could grow in medium with 4 % NaCl and 13 strains grew in pH 11 medium. Unknown strains were clustered into two new subgroups different from known species at the similarity level of 87%. Cluster 1 had three strains, of which SD109 was the central strain. Cluster 2 had four strains, and SD083 was the central strain.