Abstract: A reversed-phase high performance liquid chromatographic method was developed for determining amino acids in the root protein ,and internationally adopted nutrient value assessment method was applied to the overall assessment of the protein nutrient value .The results showed the crude protein content was 11.81％, amino acids content was 3.45%,and the total essential amino acid accounted for 39.5％ of the total amino acid.Methionine was the first limited amino acid. Chemical score(CS)，amino acid score(AAS)，essential amino acid index(EAAI)，bio1ogical value(BV)，nutritional index(NI)and score of ratio coefficient of amino acid(SRCAA)of its protein were 41.9，42.5，74.3，69.3，8.77 and 55.24 respectively．Compared with two other kinds of root crops，root protein nutrient value of sympHytum pezegrinum was higher than Rhizoma discoreae, and lower than potato. Additionally，the ratio of total delicious aminoacid content to total aminoacid content(DAA／TAA) was 42.03%, showed its good palatability and high application.