The purpose of this study was to compare the nutrition element contents of leaves and analyze its relationship with the yield of transgenic Bt cotton hybrids F₁, F₂, F₃ of NZ₆₂, H₆₄, H₁₆. The field experiments were conducted with plots at 13.4m², 4 rows, the plots were arranged in randomized complete block design with 4 replications. The field experiments were conducted in Changsha experimental base of Hunan Agricultural University in 2003 and 2004. The contents of N, P, K, B, Cu, Zn, Fe and Mn of the fourth and second leaves from the top of main cotton stems were analyzed at flowering and open boll stages. Experiment results showed that there were significant differences in the contents of N, K, B, Cu, Zn, Fe and Mn in the 4th leaves at flowering stage among different cotton hybrid combinations. All the element contents of NZ₆₂ plants was the highest, that of H16 was the second and that of H₆₄ was the lowest, the difference was significant (p<5%). There was no significant difference in the element contents of the second leaves among the transgenic Bt cotton hybrids at open boll stage. There were significant differences among the contents of N, K, Cu, Zn, Fe, Mn and B in the 4th leaves of F₁, F₂ and F₃ generations at flowering stage (p<5%), and the contents of F₁ plants were higher than F₂ and F₃, and the difference between F₂ and F₃ was not significant. F₁ plants showed higher hybrid vigor to absorb nutrition elements than F2 and F3 plants. The decreased hybrid vigor of F2 and F3 were related with the decreasing of nutrition element contents. But there was no significant difference in the element contents of the second leaves of F1, F2 and F3 plants at open boll stage（p<5%）. The results of correlation analysis showed that the cotton yields, both seed cotton yield and lint yield, were significantly positive related to N and K contents of the hybrid leaves at flowering stage, but the relationship at open boll stage was not significant（p>5%）. The positive correlation of cotton yields and the B contents in cotton plant leaves at flowering and open boll stages were highly significant（p<1%）.