This study employed a genetic model incorporating genotype and genotype-by-environment interactions to evaluate the genetic diversity of 366 long staple upland cotton germplasm resources across two growing seasons. The analysis focused on five fiber quality traits and five yield traits. We assessed phenotypic genetic diversity using correlation analysis， cluster analysis， principal component analysis， and multiple linear regression analysis to determine the potential applications of each germplasm type. The results indicated that the coefficient of variation for fiber quality traits ranged from 1.34% to 11.80%， while for yield traits it ranged from 7.95% to 54.09%. The genetic diversity index for fiber quality traits ranged from 1.55 to 2.03 （average = 1.879）， and for yield traits from 1.42 to 1.99 （average = 1.782）. These findings highlight significant differences among the 366 germplasm resources and their diverse genetic backgrounds. Cluster analysis classified their germplasm resources into five distinct groups： Group I （63 germplasms） exhibited high boll weight， high lint index， and good uniformity； Group II （41 germplasms） had high lint percentage， high boll number per plant， and high lint yield per plant （representing high-yielding materials）； Group III （71 germplasms） had short lint length and low boll weight； Group IV （84 germplasms） had longer lint length， lower micronaire value， and higher breaking tenacity； Group V （107 germplasms） had the longest lint length， lowest micronaire value， and highest breaking tenacity （high-quality materials）. Based on the comprehensive score （F-value）， 18 superior germplasms were identified， including nine with a score higher than the control variety "Jinggang" （0.87）， four with scores between "Jinggang" （0.87） and "Zhongmian-3" （0.80）， and five between "Zhongmian-3" （0.80） and "Xinluzhong-87" （0.74）. Furthermore， we developed multiple linear regression models to predict lint length and lint yield per plant. This study contributes significantly to germplasm innovation and genetic breeding in upland cotton， with the identified superior germplasms serving as exceptional parental materials for enhancing local cotton fiber quality and yield potential.