Abstract: The experiment to analyze quantitatively soil water deep drainage and nitrate leaching in fluvo-aquic soil was conducted by means of the water balance model.The experiment site,one hm ² in size was located in a piece of farmland under a rotation system of corn and wheat in the Huanghe-Huaihe-Haihe Plain.The results indicate that the volumes of soil water deep drainage and nitrate leaching are great,reaching 273.9 mm,about 60.6% of the water irrigated,and the leaching of nitrate N reaching 81.8 kg·hm ^-2,about 15.7% of the total N applied.