DNA fingerprintings of 30 main Upland cotton (Gossypium hirsutum L.) varieties were analyzed using SSR core primers.These experimental materials mainly derived from Deltapine,Stoneville,Foster and Uganda pedigrees,and they have been or are being planted in different ecological cotton-growing areas in China.Twenty pairs of 1 803 primers were confirmed as core primers with stable repeatability and rich polymorphism.These primers belonged to 15 cotton chromosomes,and amplified a total of 116 alleles with an average of 5.8.Polymorphism information content (PIC) values ranged from 0.384 to 0.900 with an average of 0.716,and marker index (MI) values ranged from 1.152 to 9.000 with an average of 4.374.Four of the 30 varieties had their specific primers,by which each variety could be distinguished from the other varieties;each of the other 26 varieties could be distinguished from the other varieties by using at least 2 pairs of primer combinations.In order to identify the 30 varieties more conveniently and accurately,their decimal digital fingerprinting codes were also constructed based on their electrophoresis patterns of the 20 core primers.This study provides important references for identification and purity detection of cotton variety,protection of intellectual property rights and standard database construction of DNA fingerprinting of Upland cotton.