Abstract: The amino acid contents and types of longan flower were analyzed based on longan germplasm.The results showed that,total free amino acid content(TAA)was up to 8 091.06mg·hg-1 with all 18 amino acid types,among them the highest amino acid was Glutamic acid(1 008.26 mg·hg-1),and the lowest was Cysteine(17.19 mg·hg-1).Glutamic acid,aspartic acid,lysine,leucine,arginine,valine,proline,seven amino acids were the major amino acids of longan flowers,accounting for 59.31% TAA content.The difference of amino acid was great among the longan genotypes,and the coefficient of variation was from 11.00% to 80.01%in 18 amino acids.The nutrition analysis showed that,the ratio of essential amino acid to total amino acid was from 38.91% to 42.94%.There were two longan genotypes with 4good amino acid model ratios,as for Shiyue longan and Dawuyuan.And(Methionine+Cysteine)was the first limiting amino acid.There were abundant in functional amino acid and tasted amino acid from different longan genotypes.The 3grading criteria of total amino acid contents was proposed based on cluster analysis,and 5longan genotypes with highest amino acid content was selected for special longan germplasm.