Amino acid was extracted from the leaves of Discoleidion rufescens by acid hydrolyzed protein method and determined the contents of amino acid. The single factor experiment and response surface experiment were applied to determine the optimum production condition with the evaluation of the ratio of amino acid extraction. The results are as follows: concentration of Hydrochloric acid 6.1mol/L, ratio of liquid to material 21.6:1, hydrolysis time 22.3h, hydrolysis temperature 100℃ with activated charcoal decoloration and ion exchange chromatography, the extract rate of amino acid was 11.2% under these conditions; the amino acid content in the product was 79.7%; the total essential amino acid content was 24%.