Objective To explore the optimum picking period for Prunella vugaris L.cultivated in a standardized way based on the determination of its main effective components.Methods Cleanolic acid and ursolic acid were taken as the representative indicators of main effective components to evaluate the optimum picking period of Prunella cultivated in the same conditions with different harvesting periods.These two components were extracted by water bathing and reflux procedures in ether as soluent and determined quantitatively by HPLC.Results As determined...