The application of organic and inorganic compound fertilizers can improve soil fertility and crop yield，but it also increases nitrous oxide(N2O)emission. In this study，reclaimed soil from Jurong city，Jiangsu province was collected for laboratory soil incubation experiment. The effects of inoculation with plant growth-promoting rhizobacteria(PGPR)on the N2O emission from soil applied with the organic and inorganic compound fertilizer were investigated. The results showed that the inoculation with PGPR strains Azospirillum sp. TSA2S，Pseudomonas stutzeri NRCB010，Achromobacter denitrificans YSQ030，and Bacillus subtilis NRCB002 significantly decreased cumulative N2O emissions from soil compared with the fertilization and non-inoculated control. The cumulative N2O emissions were as follows:NRCB002>TSA2S>NRCB010>YSQ030，which were decreased by 59%，62%，63% and 72%，respectively，after their inoculation in comparison with the non-inoculated control. The gene copy numbers of archaeal and bacterial amoA，amoB，and denitrifier nirS and nirK in soil were significantly increased after the fertilization，irrespective of inoculation with these strains or not. The inoculation with N2O-reducing denitrifier A. sp. TSA2S，P. stutzeri NRCB010，and A. denitrificans YSQ030，which possess nosZ gene，significantly increased the gene copy numbers of nosZⅠ and nosZⅡ in soil. However，the inoculation with B. subtilis NRCB002 without nosZ gene，did not change the gene copy numbers of nosZⅠ and nosZⅡ. These results suggested that these four PGPR strains decreased soil N2O emissions possibly through direct and indirect microbial-mediated mechanisms，respectively. The study will provide scientific basis and practical guidance for mitigating N2O emission from soil with organic and inorganic compound fertilizer application，and will also provide technical reference for developing novel biofertilizer with ecological and environmental effects.