Stability of 17 amino acids in 0.1% Benzoate Sodium Aqueous Solution was inspected.The 17 amino acids were prepared in 0.1% Benzoate Sodium Aqueous Solution and then derivatized with phenylisothiocyanate (PITC).High performance liquid chromatog. was taken to detect the contents of 17 amino acids materials at 0, 1, 1.5, 2, 2.5 and 3 mo, whose contents were known, the relative deviation was analyzed between the results and their contents, and the stability of the 17 amino acids was inspected through the relative deviation.All the relative deviations of amino acids materials were between 0.05%-1.1%.The aqueous solution of 17 amino acid in 0.1% Benzoate Sodium can maintain a good stability at 0-5°C storage conditions in three months, and the method can be used in the content detection of 18 Amino Acids.