Abstract: In this paper, thirty kinds of soybean from Southwest China were selected as the research object to systematically investigate the nutritional value of soybean protein by analyzing the chemical indexes of essential amino acid index and amino acid ratio coefficient. And, the nutritional quality of 30 kinds of soybean was evaluated comprehensively based on principal component analysis and cluster analysis. The results showed that the total amino acids of soybean ranged from 135.00 to 165.50 mg·g^-1, and the ratio of essential amino acids to total amino acids ranged from 36.64% to 39.01%, while the amino acid ratio coefficient was less than 100. Meanwhile, the essential amino acid index of the most soybean varieties was more than 100, and there were great differences among varieties. The first limiting amino acid was sulfur-containing amino acid, and medicinal amino acid accounted for 66.54% of the total amino acid content. Additionally, the comprehensive evaluation model based on principal component analysis could reflect the comprehensive quality of soybean protein well. Further, the 30 kinds of soybean varieties were divided into three categories based on cluster analysis, among which QD 5 and QD 11 belonged to a category with the highest evaluation, which was consistent with the results of principal component analysis.