The two maize varieties,Yuanzheng 808(astrictive type) and Sidan 19(explanate type),were cultured in pots.There were six treatments which the proportion of NO 3 - N and NH 4 + N were 1∶0 (treatment 1),2∶1(treatment 2),1∶1(treatment 3),1∶2(treatment 4),0∶1(treatment 5) and CK(no nitrogen) respectively.After emergence of seedings,the samples were picked up per 20 days in the growth period and measured chlorophyll contents,nitrate reductase(NR) activity,the weight of dry matter and single plant seed yield respectively.The result showed that enhanced ammonium nutrition (EAN) may increase chlorophyll content,dry matter weight and single plant seed yield.But there was a difference between varieties.To Yuanzheng 808,treatment 2 was the highest yield in all treatments;but treatment 4 was the highest yield to Sidan 19. The two maize varieties, Yuanzheng 808 (astrictive type) and Sidan 19 (explanate type), were cultured in pots.There were six treatments which the proportion of NO 3 -N and NH 4 + N were 1:0 (treatment 1), 2: treatment 2, 1: 1 treatment 3, 1: 2 treatment 4, 0: 1 treatment 5 and CK (no nitrogen) respectively. After emergence of the seedings, the samples were picked up per per 20 days in the growth period and measured chlorophyll contents, nitrate reductase (NR) activity, the weight of dry matter and single plant seed yield. The result showed that enhanced ammonium nutrition (EAN) may increase chlorophyll content, dry matter weight and single plant seed yield. There was a difference between varieties. To Yuanzheng 808, treatment 2 was the highest yield in all treatments; but treatment 4 was the highest yield to Sidan 19.