In this field experiment, ensilage maiz‘eZhongnongda 67’,‘Jingke 301’,‘Longyou 1’and ‘Jisi8’ were used as materials. Effects of planting density（50 000, 60 000, 70 000 and 80 000 plants/ha） and nitrogenous fertilizer level（160, 180, 200 and 220 kg/ ha） on maize growth and physiologic characteristics were studied. The results showed that among all the treatments, chlorophyll was the highest when plant density was 70 000 plants/ha and nitrogenous fertilizer 180 kg/ ha. The reductase activity was the highest when plant density was 80 000 plants/ha and nitrogenous fertilizer 200 kg/ ha. The amino acid content was the highest when plant density was 80 000 plants/ha and nitrogenous fertilizer 180 kg/ ha.