Abstract: The testing-hole experiment was conducted to investigate the effect of waterlogging at grain filling stage on the yield of maize and the leaching loss of nitrogen and phosphorus. The results showed the maximum content of total nitrogen of 2.037 and 1.833mg/L occurred in the fifth day, under the underground water table in 30 cm and in 50 cm respectively. The content of total phosphorus came to the peak value in the third day at 0.163 mg/L and 0.148 mg/L under the underground water table in 30 cm and in 50 cm respectively. Waterlogging depth of 30 cm more than 3 days and 50 cm more than 5 days can cause maize yield decreased significantly. Therefore, it is very important to control the proper underground water level and waterlogging days for corn grain formation at grain filling stage of maize in the rainy season. This research provides reference for design and management of controlled drainage in farmland.