Aimed to screen bacteria with nitrousoxide(N 2O)-reducing and plant growth-promoting abilities that provide microbial resources for the development and application of new biofertilizers. A bacterial strain named YSQ030 was isolated from the rhizosphere soil of common reed grown in apond through azotobacter mannitol agarplate，and purified on nutrient broth media containing sodium nitrate and sodium succinate. The strain was further characterized through morphologicalobservation，16S rRNA genesequencing，and physiological and biochemical characteristics analyses. The N2O-reducing activity of this strain was measured in a nitrogen-free denitrification medium.Meanwhile，the plant growth-promoting characteristics of this strain was determined under pure culture condition.Moreover，the plant growth-promoting effect on rice was determined under hydroponic condition. The results showed that the strain YSQ030 was a Achromobacter denitrificans possessing nosZ gene that encodes N2O reductase. The N2O reduction efficiency was 66.3% when YSQ030 was cultured in vial with 0% of oxygen concentration in headspace at 30℃ and 200 r/min. The strain YSQ030 could produce indole-3-aceticacid，solubilizephosphate，and synthesize 1-aminocyclopropane-1-carboxylate deaminase. The inoculation with YSQ030 significantly increased the fresh weight of rice seedlings and roots by 48.3% and 37.6% compared with the non-inoculatedcontrol，respectively，in a greenhouse hydroponic experiment. This study suggests that the strain YSQ030 has promising N2O-reducing ability and plant growth-prompting effect onrice，thereby providing invaluable microbial resources for the development of biofertilizer with N2O-reducing ability.