Abstract: To optimize the conditions for the extraction of polyphenols,using Paeonia suffruticosa ‘Feng Dan’ petals as raw material,with polyphenols content as test index to extraction. The effects of the ratio of liquid to solid,ultrasonic time,ultrasonic power and ethanol volume fraction on the polyphenols content were investigated. Experiment factors and their levels were determined by single factor test. Subsequently,the Box-Behnken experimental design was performed to optimize the conditions for polyphenols extraction. The results indicated the optimum conditions for polyphenols extraction were obtained as follows:The ratio of liquid to solid 43:1 mL/g,ultrasonic time 30 min,ultrasonic power 72 W and ethanol volume fraction 63%. Under these conditions,the best polyphenols content was(52.111±1.752)mg/g. The optimized technology applied guiding significance for the ‘Feng Dan’ petals polyphenols extraction.