To study the composition and content of free amino acids in the water extracts of three varieties from 17 different origins of mulberry leaves in Chongqing,providing theoretical basis for the development and utilization of mulberry leaves in this region.Leaves of Morus alba L.,M. cathayana Hemsl. and M. austalis Poi.from different origins were used as raw materials,the water extract was obtained by simulating mulberry leaf tea brewing method.The content of free amino acids was determined by HPLC fluorescence method and taste activity value (TAV) of 18 kinds of free amino acids was calculated.Then,the nutritional components and flavor characteristics of mulberry leaves were comprehensively evaluated by correlation analysis,principal component analysis,cluster analysis,etc.The results showed that there was no significant difference in the types of amino acids in mulberry leaves from different varieties and origins,but the content of amino acids were obvious differences.The highest content of total amino acids,essential amino acids,semi-essential amino acids and non-essential amino acids were 1 927.33 mg/100 g,322.6 mg/100 g,46.17 mg/100 g and 1 558.56 mg/100 g,respectively.Moreover,the taste characteristics of amino acids from mulberry leaves were as follows:sweet amino acids > umami amino acids > bitter amino acids.The 17 samples were divided into two categories by cluster analysis and the results showed that the samples of M. austalis Poi.(S15) and M. cathayana Hemsl.(S7) from Anlan Town in Banan District of Chongqing have high quality of amino acids.In summary,mulberry leaves are rich in amino acids and have high nutritional value,which can be used to develop amino acids functional foods.