Abstract: In order to study influence of the planting density and different fertilizer levels on the maize yield. This thesis adopted randomized complete-block design,and analysis fresh matter, dry matter, crude protein (CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF) of forage maize ‘Ruide 2’, by arranging four kinds of planting density: 60000 plants/hm2, 75000 plants/hm2, 90000 plants/hm2 and 105000 plants/hm2, and three quantities of compound fertilizer 600 kg/hm2, 750 kg/hm2, and 900 kg/hm2. The results indicated that, the single plant fresh weight and dry weight decreased with the planting density increasing, and the output of fresh matter and dry matter showed the trend of falling after rising; the percentage and output of crude protein were similar to the fresh weight and dry weight, and NDF and ADF content showed the tendency of gradual increase. The interactional function of planting density and compound fertilization was remarkable. When the planting density was 90000 plants/hm2 and compound fertilizer used 900 kg/hm2, the output of dry matter and fresh matter reached the maximum, the crude protein content also became higher. The ADF and NDF content were relatively lower, so that the output and quality were effectively improved.