Abstract:ObjectiveTo explore the optimum microwave-extracting technology of saponins from Radix Astragali with water as the solvent.MethodsTo test the effect of microwave power, size of herb particle and extraction time on the extraction efficiency by the orthogonal design method. The optimal extraction process was obtained and compared with the process of traditional ethanol extraction. ResultsMicrowave power and size of herb particle were the greatly significant factors (P <0.01). Extraction time had some effects on the extraction efficiency ( 0.05 < P <0.10). The best process was set as follows: The drug powder of 60 mesh was extracted twice for 15 minutes each, of which the quantity of water was 20 times of herbs and the power of microwave was 800 W. ConclusionCompared with traditional ethanol extraction, microwave-water-extraction can save extraction time, reduce extraction cost and has excellent extraction efficiency.