Abstract: The identification of superior parental resources adapted to the southern ecological region is of great significance for accelerating the breeding of high-yield and high-quality soybean cultivars and promoting the development of the soybean industry in southern China. In this study, 551 parental soybean germplasm accessions used in southern soybean breeding were used as materials. Frequency distribution and genetic diversity analysis were conducted for nine descriptive traits, while correlation analysis, principal component analysis, cluster analysis and comprehensive evaluation were performed for eleven quantitative traits. The results showed abundant phenotypic variation among the 551 accessions. For the nine descriptive traits, the coefficients of variation ranged from 17.45% to 102.88%, and the Shannon diversity indices ranged from 0.432 to 1.573. For the eleven quantitative traits, the coefficients of variation ranged from 6.25% to 85.24%, and the Shannon diversity indices ranged from 1.564 to 4.034. Four principal components were extracted by principal component analysis, with a cumulative contribution rate of 77.36%. Cluster analysis classified the 551 accessions into four groups: high-yield, early-maturing, short-statured and lodging-resistant, and large-seeded with high protein content. Based on principal component scores, a comprehensive evaluation function was established, and four germplasm accessions with superior comprehensive performance were identified, including one high-yield accession, two high-protein accessions, and one accession combining high yield and high protein content. These findings provide germplasm basis and theoretical reference for the breeding of new soybean cultivars in southern China.