Abstract: The Optimum extracting condition of flavonoids in Oenanthe javanica were studied,The results showedthat /40: 1 of 80% ethanol ethanol to douse the dried Oenanthe javanica for 24 hours.Ultrasonic treatment lasts for 30 minutes.twice.The extraction average rate was as high as 94.6%.

Key words: Oenan the. javanica Flavonoids Optimum extracting extracting process Ultraconic