Lysimeters experiment was carried out in a wire house study effect of microbial inoculation using three active local strains of Bradyrhizobium japonicum, Azotobacter chroococcum and Thiobacillus thioparus, some soil amendments addition as compost, sulfur, rock phosphate on soybean (Glycine max L.) cv. Giza 21. The seeds were dreseed by potassium molybdate. In rhizospheric region total count of bacteria, actinomycetes and fungi at 45, 70 and 95 days from sowing were estimated. Also true nodules formation rate, biological yield as root, shoot length, height and dry matter weight were studied. Economical yield as; number of pods, weights and weight of 100 grains as seed index were studied. In addition, determinations of total nitrogen, phosphorus and potassium in seeds and soil properties before sowing and after harvesting were done. The results obtained cleared that useful effect of combined inoculation by three bacteria under study and interaction with soil amendments addition, which resulted increase in nodulation rate (biological nitrogen fixation process), rhizosphere microbial activity followed availability of phosphorus from rock phosphate, so affect that on plant productivity, seed contain of total nitrogen, phosphorus and potassium. Also maintenance, restoring soil fertility due to these treatments. Generally, organic fertilizers with other treatments gave best results in all parameters from control. The results of this study recommended that application of combined biofertilization (Bradyrhizobium, Azotobacter and Thiobacillus) and soil amendments addition (compost, sulfur and rock phosphate) as well as seed dressing by potassium molybdate promoted rhizosphere microorganism's proliferation, plant nutrients availability, nitrogen fixation process gains due these treatments on soybean prameters and productivity, also soil maintenance and restoring fertility.