This study analyzed the quality chemical composition characteristics and genetic diversity of Camellia yungkiangensis， a special tea germplasm resource in Guizhou， in order to provide scientific basis for its development and utilization and the cultivation of new special tea varieties. 121 Camellia yungkiangensis germplasms collected from Moon Mountain， Qiandongnan Prefecture， Guizhou Province， China， were subjected to analyze 21 main quality chemical components， such as water extracts， tea polyphenols， free amino acids. Their quality characteristics and genetic diversity were evaluated by genetic diversity analysis， principal component analysis， cluster analysis， correlation analysis， and the elite resources were identified. The variation coefficient of 21 quality chemical components in 121 resources was 5.70-119.69， with an average of 32.84%， and the genetic diversity index was 1.47-2.08， with an average of 1.95. Based on the correlation analysis results of 21 quality chemical component indexes， there were 42 pairs of traits with extremely significant positive correlation， 14 pairs with significant positive correlation， 10 pairs with extremely significant negative correlation， and 10 pairs with significant negative correlation. The principal component analysis showed that the characteristic values of the first seven principal components were over 1， with the cumulative contribution rate of 76.84%. The comprehensive score of the quality chemical components of each individual plant resource on each principal component was obtained by the factor score coefficient matrix， and 12 individual plant resources with high comprehensive score of the quality chemical components were selected. Cluster analysis showed that 121 Camellia yungkiangensis germplasm resources could be divided into 6 groups at the Euclidean distance of 18.0. The 121 Camellia yungkiangensis germplasm resources were identified with high tea polyphenols （≥20.0%）， low caffeine （≤1.5%） and high theobromine （≥2.5%）， of which 72 were high tea polyphenols （≥20.0%） and high water extracts （≥45%）. These Camellia yungkiangensis germplasm resources， which showed high tea polyphenols， low caffeine and high theobromine， represent rich genetic diversity and have the potential to cultivate new varieties of specific tea plants.