Studies on isolation and characteristics of nitrogenase activity, phosphate solubilizing power and auxin (IAA) producing of associat ive symbiotic nitrogen bacteria (ASNB) from wheat rhizosphere in saline soil were carried out in Lanzhou area, Northwest China.The results show there are 12 ASNB strains obtained; Nitrogenase activities of the strains vary distinctly (C₂H₄, 124.6~651.6 nmol h^-1 ml^-1); Among the strains, two show phosphate solubilizing power with capacity reaching 16.30 g ml^-1 and 9.82 g ml^-1, respectively; nine show ability to produce auxin (IAA) although the ability varies with the strains (IAA concentration 1.40~15.13 g ml^-1).In the view of nitrogenase activity, phosphoru-s solubilizing power and IAA producing, Pseudomonas sp.ChW1, Azotobacter sp.ChW5, Zoogloea sp.ChW6 Azotobacter chroococcum ChW11 and Azospirillus sp.ChW15 show higher potential as biofertilizer inoculums for wheat in the area.