To optimize the extracting techniques for astragaloside IV from astragalus by comparing the alcohol-extraction with the water-extraction,with the extraction rate of astragaloside IV as criteria,the influencing factors on both methods of water-extraction and alcohol-extraction were studied by orthogonal test.Result: under 8 hours of soak period and grinding for astragalus,the alcohol concentration and pH shows significant influence on alcohol-extraction while only the pH shows strong influence on water-extra...