Effect of planting legume crops and inoculation of Plant Growth Promoting Rhizobacteria (PGPR) and legumes on soil building in newly-reclaimed land was studied with a field experiment laid out in a newly-reclaimed slopeland in Beibei, Chongqing, China. The experiment field was divided into several plots, which were all planted with alfalfa, but inoculated separately with nil, rhizobia or rhizobia + other PGPR (including associative azotobacters, P-releasing bacteria, and K-releasing bacteria). Results show that the incubation of rhizobium and PGPR in combination significantly increased organic matter, total N, total P and total K, available P and available K in the soil, by 33.5%, 22.7%, 3.8%, 11.5%, 11.4% and 22.3%, respectively, over the incubation of rhizobia alone and by 42.2%, 58.8%, 8%, 12.6%, 37.2% and 40.2%, respectively, over the treatment of no incubation. Furthermore, the treatment of rhizobium + PGPR also significantly increased the nodule weight, plant height, fresh root weight, fresh aboveground biomass and plant’s total nitrogen by 44.5%, 33.2%, 77.3%, 76.7% and 17.7% respectively over the treatment of rhizobia. It is obvious that plant alfalfa in combination of incubation of proper PGPR has a much better effect on soil building, thus accelerating the process of ameliorating newly-reclaimed poor land.