In this study, we analyzed the phenotypic variation of seven agronomic traits and five fiber quality traits were analyzed in 270 cotton germplasm resources. We expected to identify the upland cotton germplasm materials suitable for trait improvement, particularly interested in the Yellow River Basin and the selection of parents in future breeding work. Twelve agronomic traits showed different levels of genetic variation (boll number per plant, 24.2%; first branch length, 17.5%; first branch position, 14.1%; boll weight, 13.3%; micronaire value, 11.1%; plant height, 11.0%; lint percentage, 10.9%; fruit branch number per plant, 9.6%; fiber strength, 8.6%; upper half mean length, 6.3%; elongation ratio, 2.0%; and regularity degree, 1.6%). The upper half mean length positively correlated with plant height, and negatively correlated with micronaire value; the lint percentage positively correlated with either plant height or fiber strength, and negatively correlated with fruit branch number per plant; the micronaire value positively correlated with the elongation ratio; and the boll number per plant positively correlated with the first branch position. The cumulative contribution of the top four principal factors reached 67.358% in the principal component analysis. The first principal factor was mainly related to fiber quality; the second was mainly related to boll number per plant and first branch length; the third was mainly related to fruit branch number per plant; and the fourth was mainly related to first fruit branch number per plant position. Cluster analysis classified 270 cotton germplasms into six groups. Therefore, the cotton resources of the first cluster can be used as materials to improve the upper half mean length and fiber strength of cotton. SIMIAN 2, NANDANBADIDAHUA, EKANGMIAN8, and Qik can be used as materials for improving cotton yield; LIAO113, JUNMIAN1, LIAOYANGLVRONGMIAN, and BAO2367 can be used to improve the cotton micronaire value; and SHANSANYUAN78-782 can be used to improve the cotton type. Thus, this work provided a theoretical basis for cotton breeding by pyramiding these elite traits during breeding to cultivate new varieties and strains.