Abstract:The effects of natural high temperature on four flower traits of Gossypium barbadense L. were studied at three environmental sites in two years (Korla and Awat County in 2022 and Awat County in 2022). The high temperature tolerance of 213 Gossypium barbadense L. resources was evaluated by using 41 traits (26 quantitative traits and 15 quality traits) at different growth stages in an environmental site. Through genetic diversity analysis, principal component analysis, correlation analysis, cluster analysis, multiple regression analysis, and finally use the comprehensive evaluation value (F) to identify the better comprehensive phenotype and high temperature resistance of materials. The results showed that all 4 flower traits were easily influenced by environment, and anthers were most sensitive to high temperature. The variation coefficient and genetic diversity index of 213 Gossypium barbadense L. resources ranged from 2.70% - 30.83% and from 0.030 - 2.14 respectively, which indicated that the tested Gossypium barbadense L. resources were rich in genetic types. Nine principal components were extracted from 26 phenotypic indexes, and their cumulative contribution rate was 74.969% . They were classified into yield components, plant growth factors, and plant pollination factors. Through the multiple regression analysis, we found that the correlation between the phenotypic indexes and the pollen vigor and the exfoliation rate was not high, and the explanation rate between the pollen vigor and the exfoliation rate was not high, other phenotypic parameters had less effect. 213 Gossypium barbadense L. resources were divided into 5 groups by 26 phenotypic indexes, the first group contained 16 high-yield materials with good comprehensive characters, the second group contained 122 high-yield materials with good flower characters and big flowers, among the materials with more leaves, the third group contained 44 materials with higher plant height and lower Buds shedding rate, the fourth group contained 29 materials with better vegetative organ growth, and the fifth group contained 2 materials with stronger pollen vigor. The 213 Gossypium barbadense L. resources were divided into three groups by two high temperature tolerance indexes: the first group contained 102 high pollen vigor and low pollen Buds shedding rate materials, the second group contained 63 high pollen vigor and low pollen Buds shedding rate materials, the third category contains 48 materials with low pollen viability and high Buds shedding rate. There are 7 materials in the intersection of the two optimal clusters. The results of this study can provide a theoretical basis for the exploitation and germplasm innovation of Gossypium barbadense L.