Abstract: To investigate the effects of inoculated seeds at different amounts of nitrogen on soybean growth and yield, we conducted a randomized complete block design with three replications on the Research Farm of the Moghan College of Agriculture and Natural Resources. Treatments were 0, 50, 100 and 150 kg ha–1 urea; inoculation with Biosoy, 50 kg ha–1 urea+inoculation with Biosoy, 100 kg ha–1 urea+inoculation with Biosoy, 150 kg ha–1 urea+inoculation with Biosoy. Increasing nitrogen fertilizer in non-inoculated plants reduced nodule dry weight but enhanced plant height, stems dry weight, the pods dry weight, biological yield and grains per plant. When seeds inoculated, non-application and application of 100 kg ha–1 urea produced more stems dry weight, pods dry weight, biological yield, grain numbers per plant and grain yield which were as much as application of 150 kg ha–1 urea for non-inoculated plants. Therefore, based on this investigation results we suggest applying of diammonium phosphate as a P fertilizer at the rate of 200 kg ha–1 +non application or 50 kg ha–1 urea application plus inoculation of soybean seeds by Biosoy in Moghan region. As a result, we can save all or part of the urea fertilizer.