An improved method was described for pretreatment of standard protein hydrolyzate analysis. Adding directly the neutralizing-liquid into the hydrolysate made that the pH value of the Saple waited to analyse accorded with the demand of analysis. Then the sample was analysed with the Amino Acid Analyzer. Experiment result indicated that using this method the peak-retention-time was stabilized, the resolution was full and the analysis demands for the standard protein hydrolyzate were satisfied. Being compared with conventional pretreat ment method, the processes of heating (or freezing)and evaporating to dryness in vae evaporator were left out in this method. Besides this, the method was simple, the time was saved and the recovery of amino acids was increased distinctly.