Abstract:The amino acid content and composition late mature plums grown in Guizhou were analyzed to evaluate the nutritional quality of the fruits.Amino acid types and content were analyzed using automatic amino acid analyzer，and nutritional evaluation was carried out by evaluating the essential amino acid ratio，taste activity value，and ratio coefficient of amino acids and by performing principal component analysis.In addition to methionine，17 types of amino acids were found in plums.The total amino acid content ranged from 0.321 g/100 g to 0.842 g/100 g.Essential amino acid content ranged from 0.085 g/100 g to 0.206 g/100 g.Child essential amino acids ranged from 0.015 g/100 g to 0.041 g/100 g.The medicinal amino acid content of late mature plums after processing ranged from 0.163 g/100 g to 0.467 g/100 g.The content of fresh amino acids in the plums ranged from 0.125 g/100 g to 0.377 g/100 g.The percentage of essential amino acids/total amino acids and essential amino acids/non-essential amino acids of Chilizi were the highest（30.71% and 44.31%，respectively）.Glutamic acid，proline，and cystine contributed to the delicious taste，comfortable sweetness，and aroma，respectively，while the other amino acids contributed little to taste.The amino acid ratio coefficient ranged from 59.81 to 83.23，Wanqingcui was the highest.The nutritional value of Wanqingcui was the best according to a comprehensive evaluation of the principal components.Late mature plum in Guizhou had a complete variety of amino acids and high content，exhibited obvious differences between the germplasm of different plum varieties，and showed rich diversity.Among these plums，Wanqingcui exhibited the highest comprehensive nutritional value，had the highest amount of medicinal amino acids，delicious amino acids，and aromatic amino acids，and its essential amino acid content was adequate for human needs.