Abstract: Through objective analyzing the traits of hybrid cotton cultivar‘Sumian 29’, provide the basis for making appropriate breeding strategies for for cotton breeders. Biological characteristics of‘Sumian 29’such as high yield, stable yield, yield components, fiber quality, and resistance were studied by the statistics software Excel and G-GE based on the cotton variety regional test data of jiangsu province. Regional tests from 2010 to 2011 in Jiangsu Province showed that seed cotton yield and lint yield averaged at 4185 kg/hm², and 1737 kg/hm², and increased by 10.6% and 8.5% respectively, when compared with control cultivar (Siza 3). In production test (2012), seed cotton yield and lint yield of‘Sumian 29’averaged at 4176 kg/hm² and 1744.5 kg/ hm², respectively.‘Sumian 29’had high resistance to cotton bollworm, and also resistance to Fusarium wilt and Verticillium wilt of cotton. All the fiber qualities achieved national standard III and above. Finally,‘Sumian 29’, the genetically modified cotton cultivar, was approved by Authorized Committee of Crop Varieties of Jiangsu Province in 2013. The study preliminarily dissected the mechanism of high yield, stable yield and disease and insect resistance based on the phenotypic data and will lay the foundation for the cultivar popularization.