Abstract:The response surface methodology was used to optimize the process conditions of corn silk polyphe－ nols by ultrasonic. On the basis of single factor experiment， the ultrasonic time， ethanol concentration， and the solid-liquid ratio as the independent variables，taking gallic acid as the control， the yield of polyphenols was taken as the response value. It was used the central composite experimental method to study the effect of the variables and the interactions on the yield of polyphenolsthe and established the mathematical model of two multinomial regression equation. The results showed that it had significant effect on the extraction rate of corn silk polyphenols by the ethanol concentration. The optimal extraction process was as following： 60 % ethanol concentration， solid to liquid ratio of 1∶25（g/mL）， concentration time was 25 min， under this condition， the ex－ traction rate of the polyphenols in corn silk was 4.45 %.