Abstract: In order to maize varieties is Zhengda No.12 as material, set 5.25×104/hm2 (D1), 6.75×104/hm2 (D2), 8.25×104/hm2 (D3), 9.75×104/hm2 (D4), 11.25×104/hm2 (D5) ×104/hm2 5 planting densities, random arrangement, repeated 3 times, effect of planting density on maize yield, seek the best planting density, in order to realize the maize super high yield cultivation was created to provide technical basis. The results show that, in the D1-D5 density interval, D3 density was highest, 15696.0 kg/hm2, yield of the order from high to low was D3 > D4 > D2 > D1 > D5. Through the regression equation of maize density and yield: y=6168.905x-373.984x2 (R**=0.971614), that was ‘Zhengda No.12’, the highest yield density was 8.2476×104/hm2. The highest yield reached 25439.18 kg/hm2. Therefore, effects of different planting density on ‘Zhengda No. 12’ yield significantly, the planting density of 8.2476×104/hm2 corn yield was the highest, less than or more than the density yield significantly decreased, the Ningxia corn high yield with good guidance.