[Objectives] With the shortage of picking labor and the rising price of picking cotton,the mechanical harvesting of cotton has become the main way of harvesting cotton. It is necessary to study the effects of planting density and nitrogen application rate on cotton growth characteristics and yield under the machine harvested cotton planting mode.[Methods]The variety was ‘Xinluzhong 54’. The design was the split zone test:2 planting densities in the main area(180,240 thousand plants·hm-2),and 4 nitrogen application rates(0,170,320,470 kg·hhm-2)in the sub area.[Results]When the planting density was 240 thousand plants·hhm-2 and the nitrogen application rate was 320 kg·hhm-2,the yield and nitrogen agronomic efficiency were the highest,respectively 33.64% and 6.38 kg·kg-1. The difference was not significant with the highest yield. Under the same planting density,plant height,3rd leaf width,the number of true leaf,the number of fruit branch,stem diameter,the daily growth of the main stem and the accumulation of dry matter in the population increased with the increase of nitrogen application. Under the same nitrogen application rate,with the increase of planting density,the above traits decreased. Increasing nitrogen fertilizer and increasing planting density will prolong the growth period. When planting density was 180 thousand plants·hhm-2,leaf area index,boll number per plant,quality of single boll,lint percentage and seed cotton yield increased with the increase of nitrogen application rate. When the planting density was 240 thousand plants·hhm-2,the above traits increased first and then decreased. There was a positive correlation between agronomic traits and yield components. The increase rate and nitrogen agronomic efficiency increased first and then decreased with the increase of nitrogen application rate. The increase rate and nitrogen use efficiency increased with the increase of planting density.[Conclusions]When the density of cotton planting in southern Akesu was 240 thousand plants·hhm-2,and nitrogen application rate was 320 kg·hhm-2,the yield and nitrogen agronomic efficiency were the highest and the yield was higher. The agronomic characters conform to the standard of mechanical mining. [ABSTRACT FROM AUTHOR]