Abstract: In order to study the effects of different planting densities on nutrition characteristics and yield of cotton, a field experiment was conducted by using five planting densities from 9.0 to 27×104 plant/ha. The result shows that the highest yield is 3247.4 kg/ha under the 18.0×104 plant/ha. The N, P and K accumulation amounts at the period of boll opening and cotton yields are higher in 18×104 and 22.5×104 plant/ha. The dynamic changes of N, P and K contents of plant of cotton are decreased with the increase of density. However, the group changes are different, the N, P, K contents of group of cotton are the highest during the initial flowering and boll opening stage since the maximizing came from 15th of August, so nutrition accumulation of the latter stage was very important with the yield, especially nutrition accumulation of group and reproductive organ.