W. chinensis plants were harvested at the same farm in different months.The aerial parts of plants were air-dried , ground and extracted with 95%ethanol. After condensing, the extract was acid-hydrolyzed with HCl at pH2.0, 80°C for 1 h to enhance the aglycone flavonoid content , then neu-tralized with NaOH and applied to a flash LC system using a C18column to separate the extract into fractions. On average, the yields of W4 and W5, the major active fractions, were0.25% and0.11% from the dry plants, and2.25% and0.97% from the crude ex-tract, respectively.Together,WCE comprises0.35% from dry plant and 3.22% from crude extract, respectively. The enriched active fraction was dried, frozen and store dat-80°C for later use.