The lysine hydrochloride was transformed to amino acid dinitrofluorobenzene with 2,4-dinitrofluorobenzene, the content of lysine hydrochloride and its injection were determined by reversed HPLC.There was a good linear correlation in the range of 1.92∼9.60μg·mL-1, r = 0.9992.The average recovery of process medicine was 99.2%, RSD was 0.78% (n = 5); that of injection was 99.0%, RSD was 0.90% (n = 5).