Abstract: The objective of this study was to find if there were any differences among three Bt transgenic varieties with insect-resistance in two years. The Bt transgenic varieties with insect-resistance showed the similar trend in both seed cotton yield and lint yield in 2002 and 2003 while they showed significantly difference in fiber characters. Among the three varieties, Xinmian 33B was the best in the yield. The interaction of variety and year was obvious. Xianmian 33B yielded higher than the Check, CCRI12 in 2002 while it got similar yield with the Check in 2003. JS166 was better in seed cotton yield, lint yield, boll number per plant and boll size in two years. Moreover, JS166 got lower percentage of boll shedding in 2003. 99035 obtained the same yield as the Check. In 2002 all three Bt transgenic varieties with insect-resistance had similar fiber characters with the Check while in 2003 the fiber length and fiber uniformity were better than the Check.