Abstract:[Objective] : To study the best method to extract polyphenol from Chinese Dates in north of Shaanxi with ultrasonic wave. [Methods] : (1)select the best method and solvent; (2) The effect of single factor on the extract rate of polyphenol was observed from extract time , alcohol concentration , feed liquid ratio and an orthogonal experiment L9(33)was conducted on the base of the single factor experiment .[Results]:(1) The extraction rate by supersonic>traditional refluence>Soxhlet extraction>dipped in solvent and extracted at room temperature; The best solvent was alcohol.(2) The best technology for the extraction of the polyphenol from Chinese Dates was the alcohol concentration was 70 % (V/V), the feed liquid ratio was 1 :40 , 30min for three times with ultrasonic wave. The content of polyphenol from Chinese Dates in north of Shaanxi is 444.6mg/100g.。[Conclusions]: Extraction of polyphenol by ultrasonic wave is much better than the other method as it has shorter extraction time and lower temperature, so polyphenol would not be decomposed and we can get it easily.