The dried root of Sophora flavescens Ait (Leguminosae),a typical traditional Chinese medicine,is commonly used for the treatment of viral hepatitis,cancer,viral myocarditis,gastrointestinal hemorrhage and skin diseases (such as colpitis,psoriasis and eczema) [1].Previous phytochemical studies of Sophora flavescens Ait have reported the isolation of quinolizidine alkaloids,flavonoids and triterpenoids [2,3].For the extraction of the kurarinone and leachianone A from Sophorae radix,different ultrasonic waves (40,72 KHz) and extraction time (30,60 min) were used with different extraction solvents such as water and ethanol.The extracted samples were analyzed by reversed-phase high performance liquid chromatography coupled with mass spectroscopy (RP-HPLC-MS).In HPLC condition,the mobile phase applied was linearly changed with A/B of 80/20-65/35 vol.% for 60 min (A: water/acetic acid,99.9/0.1 vol.%,B: acetonitrile/acetic acid,99.9/0.1 vol.%).From the experimental results,the highest yield of extraction amount 6.025g was obtained by ultrasonic waves with a frequency of 72 KHz and an extraction time of 30 min.When the pre-irradiated time was increasing,the kurarinone and leachianone A yields decreased.This work offers would be useful for chemical and biological studies of S.flavescens Ait and its products.