To explore response mechanism of Artemisia selengensis on plant growthpromoting bacteria (PGPB) under cadmium stress, this study examined the effects of strain T3 on growth, physiology characteristics, cadmium concentration and translocation and rhizosphere microorganisms of A. selengensis under different concentrations of cadmium by pot experiment. The results indicated that (1) Bacillus sp.T3 could distinctly promote the accumulation of shoot,root and total dry weight, but had no significant difference in plant height and rootshoot ratio of A. selengensis under cadmium stress. (2) Bacillus sp.T3 could distinctly increase A. selengensis to cadmium concentration and translocation, bioconcentration factors (BCF) of cadmium in shoot increased by 8.3%-29.3%, translocation factors(TF) increased by 20.8%-38.3%, but BCF in root reduced by 6.6%-11.1% compared with the single cadmium stress. (3) Under the joint action of cadmium stress and Bacillus sp.T3, A. selengensis chlorophyll a, chlorophyll b and total chlorophyll contents significantly enhanced compared with the single cadmium stress. (4) Bacillus sp.T3 could significantly enhance the activities of superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT), whereas significantly reduced the malondialdehyde(MDA) content of A. selengensis. Therefore it could effectively strengthen A. selengensis to resist oxidation damage produced by cadmium stress. (5) Under cadmium stress, Bacillus sp.T3 could significantly improve the number of bacteria, actinomyces and the total number of microorganisms of A. selengensis rhizosphere soil, but could not distinctly reduce the number of fungi compared with CK. The study suggested that Bacillus sp.T3 was conducive to improve growth, physiology and rhizosphere microorganisms environment of A. selengensis and then strengthen A. selengensis adaptability to cadmium stress environment as well as tolerance.