本研究以2杂交种及其亲本自交系为试验材料，于2017年和2018年在哈尔滨开展试验，研究玉米杂交种及其亲本自交系的生产力对供氮水平的响应，及不同供氮水平下生产力的杂种优势特征。结果表明：吉单27及其亲本四287与四144单株干物质生产力对供氮水平的响应趋势相同，施氮量在0~150kg hm-2范围内，随施氮水平增加干物质积累呈递增趋势，施氮量超过150kg hm-2后，单株干物质生产力对增施氮肥无响应；四单19及其亲本444与Mo17单株干物质生产力对供氮水平的响应趋势不同，父本Mo17对施氮水平的变化没有响应。吉单27和四单19的日平均干物质积累速率均在施氮225kg hm-2处理下最高，分别为2.67和2.51g·plant-1 d-1。吉单27的单株籽粒产量对供氮水平的响应趋势与其父本四144相同，施氮量在0~150kg hm-2范围内，随施氮水平增加籽粒产量呈递增趋势，施氮量超过150kg hm-2后，单株籽粒产量对增施氮肥无响应。四单19的单株籽粒产量对供氮水平的响应趋势与其母本444相同，75、150、225和300kg hm-2 4个供氮水平下籽粒产量无显著差异，对增施氮肥没有响应；其父本Mo17对施氮与不施氮、及不同供氮水平的变化均没有响应。吉单27和四单19两个品种的单株干物质积累与籽粒产量的中亲优势、超亲优势和相对优势对供氮水平的响应趋势明显不同，吉单27在未施氮条件下单株籽粒产量中亲优势最强，四单19在高氮条件下产量中亲优势最高；不施氮的环境条件下，吉单27单株籽粒产量的杂种优势与四单19差异不明显，而在300kg hm-2的高氮条件下四单19的中亲优势和超亲优势显著强于吉单27。

In this study, 2 hybrids and their parent inbred lines were used as experimental materials, and experiments were carried out in Harbin in 2017 and 2018 to study the response of maize hybrid and their parent inbred lines to nitrogen supply levels, as well as heterosis characteristics of productivity at different nitrogen supply levels. The results showed that the dry matter productivity per plant of Jidan 27 and its parents Si 287 and Si 144 had the same response trend to the nitrogen supply level. The dry matter accumulation per plant of Jidan 27 and its parents Si 287 and Si 144 increased with the increase of nitrogen application rate in the range of 0 to 150kg ha-1, and the dry matter productivity per plant had no response to the increase of nitrogen application rate when the nitrogen application rate was more than 150kg ha-1.The dry matter productivity of Sidan 19 and its parents 444 and Mo17 were different in response to nitrogen level, while the male parent Mo17 did not respond to the change of nitrogen level. The average daily dry matter accumulation rates of Jidan 27 and Sidan 19 were the highest with 2.67 and 2.51g·plant-1 d-1, respectively, when N application was 225kg ha-1.The average accumulation rate of female parent Si 287 of Jidan 27 was 1.43 g·plant-1 d-1 at 225kg ha-1 nitrogen rate, and that of male parent Si144 was 1.96 g·plant-1 d-1 at 300kg ha-1 treatment. The average accumulation rates of 444 and Mo17 reached the maximum at the nitrogen supply level of 225kg ha-1, which were 1.35 g·plant-1 d-1 and 1.40 g·plant-1 d-1, respectively. The response trend of grain yield per plant of Jidan 27 to nitrogen supply level was the same as that of its parent Si144. The grain yield per plant of Jidan 27 increased with the increase of nitrogen application level from 0 to 150kg ha-1, but had no response to the increase of nitrogen application rate when the nitrogen application rate was more than 150kg ha-1. The response trend of grain yield per plant of Sidan 19 to nitrogen level was the same as that of parent plant 444, and there was significant difference among nitrogen application at 75, 150, 225 and 300kg ha-1 levels, and its parent Mo17 showed no response to the changes of nitrogen supply level. The mid-parent heterosis, heterobeltiosis and relative advantages of dry matter accumulation per plant and grain yield of Jidan 27 and Sidan 19 were significantly different in response to nitrogen supply level. Jidan 27 had the highet mid-parent heterosis of grain yield per plant under no nitrogen application and Sidan 19 had the highest value under the nitrogen rate of 300kg ha-1. Under the condition of no nitrogen application, the grain yield heterosis was no difference between Jidan 27 and Sidan 19, however, under the high nitrogen condition of 300kg ha-1, the mid-parent heterosis and heterobeltiosis of sidan 19 were significantly higher than that of Jidan 27.