Abstract: The method for the determination of free amino acids in Phrynium rheedei was established,and its nutritional value and flavor was evaluated. HPLC with phenylisothiocyanateas derivatization reagent,chromatographic conditions were as follows: Using C₁₈ column(4.6 mm×250 mm,5 μm),with sodium acetate buffer-acetonitrile(93∶7)and acetonitrile-water(4∶1)as mobile phrase in gradient elution,flow rate of 1.0 mL/min,column temperature of 40 ℃,the detection wavelength was set at 254 nm.The results showed that the calibration curves of 18 kinds of amino acids showed good linearity within their test ranges(R²>0.9990),and the average recovery rates of the free amino acids in Phrynium rheedei ranged from 98.3%~105.6%(RSD0.63%~3.11%,n=6). The method was stable,sebsitive,good reproducibility,and could be used to determine the content of free amino acids in Phrynium rheedei. The tested results showed that there were 18 amino acids and 8 essential amino acids in Phrynium rheedei. The total content of essential amino acids was 38.85%,which closed significantly the WHO/FAO model value(40.0%),the components of essential amino acids met the requirements of WHO/FAO amino acid model of adult. The contents of delicious amino acids and sweet amino acids were 10.73 mg/g and 5.20 mg/g,which accounted for 22.58% and 46.59% of the total respectively. The contents of Asp and Thr were more,were 3.75 mg/g and 3.33 mg/g respectively. The RCT values of Asp and Cys were 125.00 and 20.50 respectively,had more the contribution to flavour. In a word,Phrynium rheedei contains variety of amino acid,which is reasonable proportion,the content of its flavor amino acids is rich,it has broad development prospects.