Abstract: The field experiment was carried out from May 1 to October 7 in 2013. Different kinds of maize behave greatly different in aspect of absorbing and using nitrogen, so it is very essential to confirm their nitrogen quantity demanded. Effects of nitrogen fertilization can reflect on the growth of grains at their filling stage. Many scholars have done quite a lot of experiments about grain filling difference between different kinds of maize in the same condition of nitrogen application, while there are little reports applying different conditions of nitrogen application. The purpose of the experiment is to confirm the nitrogen quantity demanded, and compare the difference between different maize varieties by researching the stage of grain filling. The treatment consisted of different maize varieties (‘Tunyu99’, ‘Luyu19’, ‘Xianyu335’) and nitrogen supply rates: N0, N1, N2 (0 kg/hm², 140 kg/hm², 210 kg/hm²). The results showed that ‘Tunyu99’ grew best in N2, ‘Luyu19’ in N1 and ‘Xianyu335’ in both N1 and N2. Compared with N0, the order of different advantage in nitrogen supply was ‘Luyu19’ in N1, ‘Tunyu99’ in N2 and ‘Xianyu335’ in N1 and N2. Grains at the top position presented better development than those at the bottom in sides of weight difference. Grains of ‘Luyu19 ’dehydrate more obviously than ‘Tunyu 99’ and ‘Xianyu 335’.