Abstract: Two kinds of process method of ethanol extraction and ultrasonic-assisted extraction were be used to extract Pueraria flavonoids in this study,in order to select the better extraction method. Through experiment contrast,the process conditions of ethanol extraction are as follows: ethanol concentration is 40%,the solid-liquid ratio is 1:20,extraction temperature is 50 ℃,extracting time is 30 min. The process conditions of ultrasonic-assisted extraction are as follows: ultrasonic power is 200 W,ethanol concentration is 40%,the solid-liquid ratio is 1:20,extraction temperature is 50 ℃,extracting time is 20 min. On the premise of similar condition,extraction efficiency of Pueraria flavones was 8.03% in ultrasonic-assisted extraction,and increased by 54%.than that of the ethanol extraction. In conclusion,ultrasonic processing has the best effect and have advantages of saving time,convenient and high extraction rate.

Key words: Pueraria lobata, flavonoids, ethanol extraction, ultrasonic-assisted extraction