Abstract: Genetic improvement of main traits was analyzed using 110 China-bred cottons with Fusarium and Verticillium wilts resistance released since 1950’s.The results indicated that a great progress for Fususium wilt resistance breeding had been achieved, but progress for Verticillium wilt resistance breeding was slow. Yield of per plant showed an up trend except for 1970’s varieties. The mean of boll number per plant was no significant variation among different years. Lint percentage of the varieties showed a downtrend from 1950’s to 1970’s and an up trend from 1970’s to 1990’s. Growing period of the varieties became short from 1950’s to 1990’s, and there was a down trend of plant height, first fruit branch node, distance between the first fruit branch and cotyledon from 1960’s to 1990’s.