Abstract: The purpose of the article was to study our country’s upland cotton’s variation in genetic traits between different growth periods. Based on the database of 836 upland cotton cultivars registered from Yellow River, Yangtze River and Xinjiang cotton production zone during 1978-2007, the variation trends of total 14 agricultural traits such as growth period, plant height, sympodial branch node, boll weight, lint percentage, fiber yield, fiber length, fiber strength and others were analyzed in this study. The results showed that the boll weight and fiber yield, especially fiber strength were increasing along with time passed in all three production zones. The planting density in Yellow River and Yangtze River production zones were decreasing along with time passed, however, the planting density of Xinjiang production zone were increasing. The variation of leaf color, sympodial branch node, boll shape, micronaire, fusarium wilt, and verticillium wilt resistance were significant in different years and the growth period, but lint percentage and fiber length were stable. The plant height showed no significant variation since the 90’s. This study demonstrated that the agricultural traits of cotton varieties registered since 1978 were stable and well in China, the yield and fiber quality, especially the fiber strength, were obviously improved. However, further improvements in micronaire, fusarium wilt, and verticillium wilt resistance were still needed.