Abstarct: To evaluate the effect of irrigation and Nitroxin on growth and yield of soya as a second crop after wheat, an experiment was conducted in summer 1391 in Gorgan. This experiment was done in factorial and in a randomized complete block design with three replications. Treatments included irrigation at three levels: 6, 15 and 23 as the first agent following the onset of jointing practices and four levels Nitroxin control(non - consumption),1, 2 and 3 kilograms per hectare in seed as the second factor. The results of this survey showed that with increasing irrigation interval from 6 to 23 days, grain, plant height, the distance of the last pod in the main stem of the ground, the total number of filled pods, the number of seed per plant, the number of nodes, 100 grain weight, the number fertile branches per plant, protein yield, leaf area index, biological yield and grain harvest index reduced, and Nitroxin was a significant effect of increasing the yield.