At Green house, Soil Science, Department, Faculty of Agriculture, Menoufia University , Shibin El-Kom, Menoufia Governorate, Egypt during growing summer season of 2022 this study was carried out as a pots experiment. This study was established to evaluate the efficiency of biofertilizers affected by quality of irrigation water and their effect on biological activity, N-fixation and soybean (Glycine max L.) plant growth. the measurments increased significantly with biofertilization inoculation, where the found increases in the plants inoculated by R2 were higher than those resulted from inoculation with R1.Also, similar effect was found with length roots and shoots (cm) as well as fresh and dry weights (g/ plant) of soy bean plants value. Concentration (%) and uptake (mg ∕ plant) of N, P and K by shoots of soybean plants varried significantly within the studied treatments. The highest content of N, P and K was found in the plants irrigated by WW. Also, the contents in the plants fertilized by R2 were higher than these inoculated by R1. Nitrogenase activity appeared to have a high response for irrigation water quality and biofertilization. With the same biofertilizers, the highest value of nitrogenase was found in the soil irrigated by WW, while the lowest one was found in the soil irrigated by SW. As well as , inoculation with R2 increased nitrogenase activity than that from inoculation with R1.This means that , biofertilizers inoculation is very important with irrigation using low quality resources of water irrigation.