Abstract: 【Objective】 To carry out association analysis of plant height of 185 upland cotton cultivars during the cotton flowering stage (PH-ST₁) and spikelike inflorescence period (PH-ST₂) to investigate the superior alleles variation of dynamic plant height. Which can provide a guidance for further high-yield molecular marker-assisted selection breeding of upland cotton. 【Methods】 355 polymorphism loci developed from 137 pairs of SSR polymorphism primers were combined with plant height phenotype data from two periods in five environments, and the general linear model (GLM) and mixed linear model (MLM) were used for association analysis by the genotypes of 185 upland cotton varieties. 【Results】 54 and 12 alleles in PH-ST₁ were detected by the GLM and MLM model, respectively. Meanwhile, 62 and 12 alleles in PH-ST₂ were detected by the GLM and MLM model. Among them, 31 loci were significantly related to plant height in 3 or more environments. 【Conclusion】 Through correlation analysis, multiple molecular markers that can be repeatedly detected and associated with the height of upland cotton were excavated.The 24 loci were reported.