Abstract: Taking the protein extraction rate as a measure indicator, ultrasonic-assisted technology was used to extract the protein from corn germ meal. By single factor investigation and response surface methodology, the optimum extraction conditions were obtained : ratio of liquid : material at 25 ∶ 1m L / g, ultrasonic power 120 W, ultrasonic time 40 min, and p H value 10. Under these conditions, the protein extraction yield ratio reached41.93%. Compared with the alkali method extraction, protein extraction rate of corn germ meal was improved by ultrasonic-assisted extraction. Furthermore, ultrasound-assisted extraction could be finished under room temperature and the extraction time was greatly shortened.