An experiment was conducted to study the effects solvent concentration,material granularity,ratio of sample weight to solvent volume,extraction temperature,extraction time,extraction times on the extraction ratio of oligoprocyanidins from the root of Sanguisorba officinalis.The optimal extraction conditions were obtained as extraction solvent 60% alcohol-water solution,material granularity 40~60 mesh,ratio of sample weight to solvent volume 1∶12,extraction temperature 50 degree C,extraction 1hours and extra...